func_code_string: #include <bits/stdc++.h>   using namespace std;   void solve() {     long long n, i, m, s = 0, d = 0;     cin >> n >> m;     long long a[n], b[n], c[n];     for (i = 0; i < n; i++) {       cin >> a[i] >> b[i];       s += a[i];       c[i] = a[i] - b[i];     }     sort(c, c + n);     for (i = 0; i < n; i++)       if (s > m) {         s = s - c[n - 1 - i];         d++;       }     if (s > m)       cout << -1;     else       cout << d;   }   int main() {     long long a;     solve();     return 0;   }   