0分求助！

#include<bits/stdc++.h>
using namespace std;
struct zhandian{
    int p,c;
};
struct huoche{
    int a,b;
    int cha;
};
bool cmp1(zhandian _1,zhandian _2){
    return _1.p<_2.p;
}
bool cmp2(huoche _1,huoche _2){
    return _1.cha>_2.cha;
}
int n,m,x;
zhandian a[100005];
huoche b[100005];
int main(){
    int ans=0,xiao=0;
    cin>>n>>m>>x;
    for(int i=0;i<n;i++){
        cin>>a[i].p>>a[i].c;
    }
    for(int i=0;i<m;i++){
        cin>>b[i].a>>b[i].b;
        b[i].cha=b[i].a-b[i].b;
        if(b[i].cha>=0)xiao=i;
    }
    sort(a,a+n,cmp1);
    sort(b,b+n,cmp2);
    int nows=0;
    for(int i=0;i<=xiao;i++){
        if(a[nows].c==0)nows++;
        a[nows].c--;
        ans+=b[i].a*a[nows].p+b[i].b*(x-a[nows].p);
    }
    nows=n-1;
    for(int i=m-1;i>xiao;i--){
        if(a[nows].c==0)nows--;
        a[nows].c--;
        ans+=b[i].a*a[nows].p+b[i].b*(x-a[nows].p);
    }
    cout<<ans;
    return 0;
}