diff --git a/storage/zeta/cpp/completed/10816.cpp b/storage/zeta/cpp/completed/10816.cpp
new file mode 100644
index 0000000..55a6828
--- /dev/null
+++ b/storage/zeta/cpp/completed/10816.cpp
@@ -0,0 +1,42 @@
+#include <map>
+#include <iostream>
+
+using namespace std;
+
+void fastio() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(nullptr);
+    cout.tie(nullptr);
+}
+
+int main() {
+    fastio();
+    int n;
+    cin >> n;
+    map<int, int> 상근이카드;
+
+    int x;
+    for (auto i = 0; i < n; i++) {
+        cin >> x;
+        auto pos = 상근이카드.find(x);
+        if (pos == 상근이카드.end()) {
+            상근이카드[x] = 1;
+        } else {
+            pos->second++;
+        }
+    }
+
+    int m;
+    cin >> m;
+
+    for (auto i = 0; i < m; i++) {
+        cin >> x;
+        auto pos = 상근이카드.find(x);
+        if (pos == 상근이카드.end()) {
+            cout << "0 ";
+        } else {
+            cout << pos->second << " ";
+        }
+    }
+    cout << "\n";
+}
\ No newline at end of file
diff --git a/storage/zeta/cpp/completed/1764.cpp b/storage/zeta/cpp/completed/1764.cpp
new file mode 100644
index 0000000..86696a8
--- /dev/null
+++ b/storage/zeta/cpp/completed/1764.cpp
@@ -0,0 +1,55 @@
+#include <iostream>
+#include <set>
+#include <string>
+#include <algorithm>
+#include <vector>
+#include <iterator>
+
+using namespace std;
+
+void fastio() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(nullptr);
+    cout.tie(nullptr);
+}
+
+int main() {
+    fastio();
+
+    int n, m;
+
+    cin >> n >> m;
+
+    auto 듣도못한사람 = new set<string>();
+    auto 보도못한사람 = new set<string>();
+    for (auto i = 0; i < n; i++) {
+        string name;
+        cin >> name;
+        듣도못한사람->insert(name);
+
+
+    }
+
+    for (auto j = 0; j < m; j++) {
+        string name;
+        cin >> name;
+        보도못한사람->insert(name);
+    }
+
+    auto 듣도보도못한사람 = new vector<string>();
+    set_intersection(
+            듣도못한사람->begin(), 듣도못한사람->end(),
+            보도못한사람->begin(), 보도못한사람->end(),
+            back_inserter(*듣도보도못한사람)
+    );
+
+    cout << 듣도보도못한사람->size() << "\n";
+    for (auto name: *듣도보도못한사람) {
+        cout << name << "\n";
+    }
+
+    delete 듣도못한사람;
+    delete 보도못한사람;
+    delete 듣도보도못한사람;
+
+}
\ No newline at end of file
diff --git a/storage/zeta/kt/completed/25793.kt b/storage/zeta/kt/completed/25793.kt
new file mode 100644
index 0000000..de69b38
--- /dev/null
+++ b/storage/zeta/kt/completed/25793.kt
@@ -0,0 +1,36 @@
+import kotlin.math.min
+
+fun chocolatePyramidSum(r: Int, c: Int): Long {
+    val m = min(r, c).toLong()
+    return m * (4 * m * m - 6 * m * (r.toLong() + c.toLong()) + 12 * r.toLong() * c.toLong() - 1) / 3
+}
+
+fun chocolatePyramidDark(r: Int, c: Int): Long {
+    val m = min(r, c).toLong()
+    return m * (2 * m * m - 3 * m * (r.toLong() + c.toLong()) + 6 * r.toLong() * c.toLong() - 2) / 3
+}
+
+fun chocolatePyramid(r: Int, c: Int): Pair<Long, Long> {
+    // W(r, c) = (r * c) + (r-1) * (c-1) + D(r-1, c-1)
+    // D(r, c) = (r - 1) * c + r * (c-1) + W(r-1, c-1)
+    // therefore,
+    // W(r, c) = (r * c) + 2*(r-1)*(c-1) ...(until r-k or c-k is equal to 0)
+    // D(r, c) = (r - 1) * c + r * (c-1) + (r-2) * (c-1) + (r - 1) * (c-2)
+    //(r*c) + (r-1) * c + r * (c-1) + (r-1) * (c-1)
+    // S(r, c) = (2r-1)(2c-1) + S(r-1, c-1)
+
+    val s = chocolatePyramidSum(r, c)
+    val d = chocolatePyramidDark(r, c)
+    return s - d to d
+}
+
+fun main() = with(System.`in`.bufferedReader()) {
+    val t = this.readLine().toInt()
+    repeat(t) {
+        val (r, c) = this.readLine().split(" ").map { it.toInt() }
+
+        println(chocolatePyramid(r, c).let {
+            "${it.first} ${it.second}"
+        })
+    }
+}
\ No newline at end of file