diff --git a/src/2/15/T316693.cpp b/src/2/15/T316693.cpp
new file mode 100644
index 0000000..7289a83
--- /dev/null
+++ b/src/2/15/T316693.cpp
@@ -0,0 +1,46 @@
+#include <bits/stdc++.h>
+#include <cstdint>
+
+using namespace std;
+using ll = int64_t;
+
+ll cgcd(ll a, ll b){
+    while(b){
+        ll temp = a % b;
+        a = b;
+        b = temp;
+    }
+    return a;
+}
+
+ll phi(ll n){
+    if(n == 0) return 0;
+    ll res = n;
+    for(ll p=2; p*p <= n; p++){
+        if(n % p == 0){
+            while(n % p ==0){
+                n /= p;
+            }
+            res -= res / p;
+        }
+    }
+    if(n > 1){
+        res -= res / n;
+    }
+    return res;
+}
+
+int main(){
+    ios::sync_with_stdio(false);
+    cin.tie(0);
+    int T;
+    cin >> T;
+    while(T--){
+        ll a, m;
+        cin >> a >> m;
+        ll d = cgcd(a, m);
+        ll mp = m / d;
+        ll ans = phi(mp);
+        cout << ans << "\n";
+    }
+}
\ No newline at end of file
diff --git a/src/2/15/T574007.cpp b/src/2/15/T574007.cpp
new file mode 100644
index 0000000..8d69f3c
--- /dev/null
+++ b/src/2/15/T574007.cpp
@@ -0,0 +1,96 @@
+#include <algorithm>
+#include <bitset>
+#include <cstddef>
+#include <cstdint>
+#include <iostream>
+#include <istream>
+#include <limits>
+#include <vector>
+
+using ll = int64_t;
+
+
+constexpr ll maxn = 1e3;
+constexpr ll maxa = 10000100;
+
+ll n, m;
+ll arr[maxn + 5][maxn + 5];
+ll cm[maxn + 5][maxn + 5];
+ll cr[maxn + 5], ca[maxn + 5];
+ll ans = std::numeric_limits<ll>::max();
+ll np[maxa + 5];
+
+std::bitset<10000105> bs;
+
+int main() {
+  std::ios::sync_with_stdio(false);
+  std::cin.tie(nullptr);
+  std::cout.tie(nullptr);
+
+  bs.set();
+  bs.reset(0);
+  bs.reset(1);
+
+  for (ll i = 2; i * i <= maxa; ++i) {
+    if (bs[i]) {
+      for (ll j = i * i; j <= maxa; j += i) {
+        bs[j] = false;
+      }
+    }
+  }
+
+  ll nnp = std::numeric_limits<ll>::max();
+  for (ll i = maxa; i >= 0; --i) {
+    if (bs[i]) {
+      nnp = i;
+    }
+    np[i] = nnp;
+  }
+
+  std::cin >> n >> m;
+  for (ll i = 0; i < n; i++) {
+    for (ll j = 0; j < m; j++) {
+      std::cin >> arr[i][j];
+
+      if (arr[i][j] > maxa) {
+
+        arr[i][j] = maxa;
+      }
+    }
+  }
+
+  for (ll i = 0; i < n; i++) {
+    for (ll j = 0; j < m; j++) {
+      cm[i][j] = np[arr[i][j]] - arr[i][j];
+    }
+  }
+
+  for (ll i = 0; i < n; i++) {
+    ll row_total = 0;
+    for (ll j = 0; j < m; j++) {
+      row_total += cm[i][j];
+    }
+    cr[i] = row_total;
+  }
+
+  for (ll j = 0; j < m; j++) {
+    ll ct = 0;
+    for (ll i = 0; i < n; i++) {
+      ct += cm[i][j];
+    }
+    ca[j] = ct;
+  }
+
+  for (ll i = 0; i < n; i++) {
+    for (ll j = 0; j < m; j++) {
+
+      ll ccc =
+          cr[i] + ca[j] + (bs[arr[i][j]] ? 0 : -cm[i][j]);
+      if (ccc < ans) {
+        ans = ccc;
+      }
+    }
+  }
+
+  std::cout << ans << '\n';
+}
\ No newline at end of file