史上最简AC代码：

#include<bits/stdc++.h>
using namespace std;
int main(){ int g,yuan=8; char fu; cin>>g>>fu; if(g<=1000&&fu=='y'){cout<<13; return 0;} if(g<=1000&&fu=='n'){cout<<8; return 0;} g-=1000; while(g>0){yuan+=4; g-=500;} if(fu=='y') cout<<yuan+5; else cout<<yuan; return 0;}

看不懂的话看下面：

#include<bits/stdc++.h>
using namespace std;

int main(){
    int g,yuan=8;
    char fu;
    cin>>g>>fu;
    if(g<=1000&&fu=='y'){cout<<13; return 0;}
    if(g<=1000&&fu=='n'){cout<<8; return 0;}
    g-=1000;
    while(g>0){yuan+=4; g-=500;}
    if(fu=='y') cout<<yuan+5;
    else cout<<yuan;
    return 0;
}