func_code_string: #include <bits/stdc++.h>   const int INF = 1e9 + 7;   int ds[100];   int hs[100];   int solve() {     int N, X;     scanf( %d %d , &N, &X);     for (int i = 0; i < N; i++) {       scanf( %d %d , &ds[i], &hs[i]);     }     int last = *std::max_element(ds, ds + N);     if (last >= X) return 1;     int dec = 0;     for (int i = 0; i < N; i++) {       dec = std::max(dec, ds[i] - hs[i]);     }     if (dec == 0) return -1;     return (X - last + dec - 1) / dec + 1;   }   int main() {     int T;     scanf( %d , &T);     while (T--) {       printf( %d n , solve());     }   }   