diff --git a/src/main/java/contest/y2022/m7/Dw83.java b/src/main/java/contest/y2022/m7/Dw83.java
new file mode 100644
index 0000000..615c2a7
--- /dev/null
+++ b/src/main/java/contest/y2022/m7/Dw83.java
@@ -0,0 +1,72 @@
+package contest.y2022.m7;
+
+import java.lang.reflect.Array;
+import java.util.Arrays;
+
+public class Dw83 {
+    public static void main(String[] args) {
+        Dw83 solution = new Dw83();
+    }
+
+    public int shortestSequence(int[] rolls, int k) {
+        int cnt = 1;
+        boolean[] uses = new boolean[k + 1];
+        int use = k;
+        for (int i = 0; i < rolls.length; i++) {
+            if (!uses[rolls[i]]) {
+                uses[rolls[i]] = true;
+                use--;
+            }
+            if (use == 0) {
+                cnt++;
+                Arrays.fill(uses, false);
+                use = k;
+            }
+        }
+        return cnt;
+    }
+
+    public long zeroFilledSubarray(int[] nums) {
+        long cnt = 0;
+        int[] cnts = new int[nums.length];
+        if (nums[0] == 0) {
+            cnts[0] = 1;
+            cnt = 1;
+        }
+        for (int i = 1; i < nums.length; i++) {
+            if (nums[i] == 0) {
+                cnts[i] = cnts[i - 1] + 1;
+                cnt += cnts[i];
+            }
+        }
+        return cnt;
+    }
+
+    public String bestHand(int[] ranks, char[] suits) {
+        boolean bl = true;
+        int max = 1;
+        int cnt = 1;
+        Arrays.sort(ranks);
+        for (int i = 1; i < 5; i++) {
+            if (suits[i] != suits[i - 1]) {
+                bl = false;
+            }
+            if (ranks[i] == ranks[i - 1]) {
+                cnt++;
+            } else {
+                max = Math.max(max, cnt);
+                cnt = 1;
+            }
+        }
+        max = Math.max(max, cnt);
+        if (bl) {
+            return "Flush";
+        } else if (max >= 3) {
+            return "Three of a Kind";
+        } else if (max == 2) {
+            return "Pair";
+        } else {
+            return "High Card";
+        }
+    }
+}
diff --git a/src/main/java/contest/y2022/m7/NumberContainers.java b/src/main/java/contest/y2022/m7/NumberContainers.java
new file mode 100644
index 0000000..b7d488f
--- /dev/null
+++ b/src/main/java/contest/y2022/m7/NumberContainers.java
@@ -0,0 +1,32 @@
+package contest.y2022.m7;
+
+import java.util.*;
+
+public class NumberContainers {
+    Map<Integer, Integer> nums;
+    Map<Integer, TreeSet<Integer>> map;
+
+    public NumberContainers() {
+        nums = new HashMap<>();
+        map = new HashMap<>();
+    }
+
+    public void change(int index, int number) {
+        if (nums.containsKey(index)) {
+            map.get(nums.get(index)).remove(index);
+        }
+        nums.put(index, number);
+        TreeSet<Integer> list = map.getOrDefault(number, new TreeSet<>());
+        list.add(index);
+        map.put(number, list);
+    }
+
+    public int find(int number) {
+        TreeSet<Integer> list = map.getOrDefault(number, new TreeSet<>());
+        if (list.size() > 0) {
+            return list.first();
+        } else {
+            return -1;
+        }
+    }
+}