func_code_string: #include <bits/stdc++.h>   using namespace std;   const double eps = 1e-6;   const int N = 101;   const int INF = 0x3f3f3f3f;   const int mod = 1000000007;   long long powmod(long long a, long long b) {     long long res = 1;     a %= mod;     assert(b >= 0);     for (; b; b >>= 1) {       if (b & 1) res = res * a % mod;       a = a * a % mod;     }     return res;   }   int a[N], maxf, ans;   int d[N];   bool mul;   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     int n, m;     cin >> n >> m;     for (int i = 0; i < m; i++) {       int k, f;       cin >> k >> f;       a[k] = f;       maxf = max(maxf, f);     }     int now = 1;     for (; now <= 100; now++) {       int line = 1;       bool ok = 1;       for (int i = 1; i <= 100; i++) {         if (a[i] && a[i] != line) {           ok = 0;           break;         }         if (i == n && ans && d[n] != line) {           mul = 1;         }         if (i % now == 0) {           line++;         }       }       if (mul && ok) {         ans = -1;         break;       }       if (ok) {         line = 1;         for (int i = 1; i <= 100; i++) {           d[i] = line;           if (i % now == 0) {             line++;           }         }         ans = d[n];       }     }     cout << ans << endl;     return 0;   }   