func_code_string: #include <bits/stdc++.h>   #pragma warning(disable : 4996)   using namespace std;   template <class T>   inline void chkmin(T &a, T b) {     if (a > b) a = b;   }   template <class T>   inline void chkmax(T &a, T b) {     if (a < b) a = b;   }   int main() {     int n, m;     cin >> n >> m;     --n;     int l = 1, r = 1000;     for (int i = 0; i < m; ++i) {       int k, first;       cin >> k >> first;       chkmax(l, (k + first - 1) / first);       if (first != 1) chkmin(r, (k - 1) / (first - 1));     }     int f1 = n / l + 1;     int f2 = n / r + 1;     if (f1 != f2)       cout <<  -1 n ;     else       cout << f1 <<   n ;   }   