func_code_string: #include <bits/stdc++.h>   using namespace std;   pair<int, int> arr[100001];   int main() {     int n, d, a, b;     cin >> n >> d >> a >> b;     for (int i = 0; i < n; i++) {       int c, d;       cin >> c >> d;       arr[i].first = c * a + d * b;       arr[i].second = i + 1;     }     sort(arr, arr + n);     long long counter = 0;     int in = n;     for (int i = 0; i < n; i++) {       counter += arr[i].first;       if (counter > d) {         in = i;         break;       }     }     cout << in << endl;     for (int i = 0; i < in; i++) {       cout << arr[i].second <<    ;     }     cout << endl;     return 0;   }   