```cpp
#include<bits/stdc++.h>
using namespace std;
int a[10005],x,y,price=0,dj,maxm;
int main(){
cin>>x>>y;
for(int i=0;i<y;i++){
cin>>dj>>maxm;
a[dj]=a[dj]+maxm;
}
for(int i=0;i<1000;i++){
if(x>a[i]){
x-=a[i];
price=price+a[i]*i;
}else if(x>0){
price+=x*i;
x=0;
}else if(x=0){
break;
}
}
cout<<price;
return 0;
}
```
by wsh88 @ 2023-06-02 20:03:16
请求关注
by wsh88 @ 2023-06-02 20:03:59