tjut 3090

#include <iostream>#include <stdio.h>#include <algorithm>using namespace std;struct Node{int d,p;};Node roads[10001];int n,m;int sum;bool cmp(const Node & n1,const Node & n2){return n1.p > n2.p;}int main(){while(scanf("%d %d", &n, &m), m!=0 || n!=0){sum = 0;for(int i=0; i<n; i++){scanf("%d%d", &roads[i].d, &roads[i].p);sum += roads[i].d*roads[i].p;}sort(roads, roads+n, cmp);for(int i=0; i<n; i++){if(m > roads[i].d){m -= roads[i].d;sum -= roads[i].d * roads[i].p;        }else{            sum -= m * roads[i].p;            break;        }}printf("%d\n",sum);}return 0;}