func_code_string: #include <bits/stdc++.h>   #pragma GCC target( avx2 )   #pragma GCC optimization( O3 )   #pragma GCC optimization( unroll-loops )   #pragma GCC optimize( Ofast )   #pragma GCC target( avx,avx2,fma )   using namespace std;   long long binpow(long long base, long long exp, int mod) {     long long res = 1;     while (exp > 0) {       if (exp % 2 == 1) res = (res * base) % mod;       exp = exp >> 1;       base = (base * base) % mod;     }     return res;   }   long long mod(long long x) {     return ((x % 1000000007LL + 1000000007LL) % 1000000007LL);   }   long long add(long long a, long long b) { return mod(mod(a) + mod(b)); }   long long mul(long long a, long long b) { return mod(mod(a) * mod(b)); }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     ;     long long int t;     cin >> t;     while (t--) {       long long int n, m;       cin >> n >> m;       long long int maxdiff = -1e18;       long long int maxele = -1e18;       for (int i = 0; i < n; i++) {         long long int l, r;         cin >> l >> r;         maxdiff = max(maxdiff, l - r);         maxele = max(maxele, l);       }       long long int ans = 1;       m -= maxele;       if (m > 0) {         if (maxdiff <= 0) {           ans = -1;         } else {           ans += (m + maxdiff - 1) / maxdiff;         }       }       cout << ans <<   n ;     }     return 0;   }   