diff --git a/src/main/java/com/code/leet/doubleWeek/SolutionD60.java b/src/main/java/com/code/leet/doubleWeek/SolutionD60.java
new file mode 100644
index 0000000..32bdd68
--- /dev/null
+++ b/src/main/java/com/code/leet/doubleWeek/SolutionD60.java
@@ -0,0 +1,157 @@
+package com.code.leet.doubleWeek;
+
+import java.math.BigInteger;
+import java.util.*;
+
+public class SolutionD60 {
+    public static void main(String[] args) {
+        SolutionD60 solution = new SolutionD60();
+        solution.numberOfGoodSubsets(new int[]{4, 2, 3, 15});
+    }
+
+    public int findMiddleIndex(int[] nums) {
+        int[] sums = new int[nums.length + 1];
+        for (int i = 0; i < nums.length; i++) {
+            sums[i + 1] = sums[i] + nums[i];
+        }
+        for (int i = 1; i < sums.length; i++) {
+            if (sums[i - 1] == sums[sums.length - 1] - sums[i]) {
+                return i - 1;
+            }
+        }
+        return -1;
+    }
+
+    public int[][] findFarmland(int[][] land) {
+        boolean[][] use = new boolean[land.length][land[0].length];
+        int[] xIndex = new int[]{1, 0};
+        int[] yIndex = new int[]{0, 1};
+        List<int[]> list = new ArrayList<>();
+        for (int i = 0; i < land.length; i++) {
+            for (int j = 0; j < land[0].length; j++) {
+                if (land[i][j] == 1 && !use[i][j]) {
+                    Queue<int[]> queue = new LinkedList<>();
+                    queue.add(new int[]{i, j});
+                    use[i][j] = true;
+                    int[] temp = new int[]{i, j, i, j};
+                    while (!queue.isEmpty()) {
+                        int[] arr = queue.poll();
+                        for (int k = 0; k < 2; k++) {
+                            int x = arr[0] + xIndex[k];
+                            int y = arr[1] + yIndex[k];
+                            if (x >= land.length || y >= land[0].length || land[x][y] == 0 || use[x][y]) {
+                                continue;
+                            }
+                            if (x > temp[2] || y > temp[3]) {
+                                temp[2] = x;
+                                temp[3] = y;
+                            }
+                            use[x][y] = true;
+                            queue.add(new int[]{x, y});
+                        }
+                    }
+                    list.add(temp);
+                }
+            }
+        }
+        int[][] result = new int[list.size()][4];
+        for (int i = 0; i < list.size(); i++) {
+            result[i] = list.get(i);
+        }
+        return result;
+    }
+
+//    class LockingTree {
+//
+//        int[] parent;
+//        boolean[] isLock;
+//        int[] userLock;
+//
+//        public LockingTree(int[] parent) {
+//            this.parent = parent;
+//            isLock = new boolean[parent.length];
+//            userLock = new int[parent.length];
+//            Arrays.fill(userLock, -1);
+//        }
+//
+//        public boolean lock(int num, int user) {
+//
+//        }
+//
+//        public boolean unlock(int num, int user) {
+//
+//        }
+//
+//        public boolean upgrade(int num, int user) {
+//
+//        }
+//    }
+
+    long temp;
+
+    public int numberOfGoodSubsets(int[] nums) {
+        int[] counts = new int[31];
+        List<Integer> list = new ArrayList<>(Arrays.asList(2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 29, 30));
+        long sum = 0;
+        for (int num : nums) {
+            counts[num]++;
+        }
+        int count = 0;
+        for (int i = 1; i < 31; i++) {
+            if (list.contains(i)) {
+                count += counts[i];
+            }
+        }
+        if (counts[1] > 0) {
+            sum += (long) counts[1] * count;
+        }
+        for (int i = list.size() - 1; i >= 0; i--) {
+            if (counts[list.get(i)] == 0) {
+                list.remove(i);
+            }
+        }
+        Map<Integer, List<Integer>> pd = new HashMap<>();
+        pd.put(2, Arrays.asList(2, 6, 10, 14, 22, 26, 30));
+        pd.put(3, Arrays.asList(3, 6, 15, 21, 30));
+        pd.put(5, Arrays.asList(5, 10, 15, 30));
+        pd.put(7, Arrays.asList(7, 14, 21));
+        pd.put(11, Arrays.asList(11, 22));
+        pd.put(13, Arrays.asList(13, 26));
+        pd.put(17, Collections.singletonList(17));
+        pd.put(19, Collections.singletonList(19));
+        pd.put(23, Collections.singletonList(23));
+        pd.put(29, Collections.singletonList(29));
+        boolean[] use = new boolean[31];
+        dfs(list, use, 0, 0, pd, counts);
+        sum += (long) nums[0] * (nums[0] + 1) / 2 * temp;
+        return (int) (sum % 1000000007);
+    }
+
+    private void dfs(List<Integer> list, boolean[] use, long count, int index, Map<Integer, List<Integer>> pd, int[] counts) {
+        if (index == list.size()) {
+            temp = count;
+        }
+        int t = 0;
+        boolean bl = true;
+        List<Integer> l = new ArrayList<>();
+        for (int key : pd.keySet()) {
+            if (pd.get(key).contains(list.get(index))) {
+                if (!use[key]) {
+                    l.add(key);
+                } else {
+                    bl = false;
+                }
+            }
+        }
+        if (bl) {
+            for (Integer integer : l) {
+                use[integer] = true;
+            }
+            dfs(list, use, Math.max(0, 1) * counts[list.get(index)], index + 1, pd, counts);
+            for (Integer integer : l) {
+                use[integer] = false;
+            }
+        }
+        dfs(list, use, count, index + 1, pd, counts);
+    }
+}