零分求助

#include<cstdio>
#include<iostream>
#include<cmath>
using namespace std;
int read()
{
    int s=0,w=-1;
    char ch=getchar();
    while(ch<'0' || ch>'9'){if(ch=='-')w=-1;ch=getchar();}
    while(ch>='0' && ch<='9')s=s*10+ch-'0',ch=getchar();
    return s*w;
}
int wky,wang,n,m,k;
const int Maxn=5e3+5;
int w[Maxn],c[Maxn],lev[Maxn],f[Maxn];
int main()
{
    wky=read(),wang=read(),n=read(),k=read();
    for(int i=1;i<=k;++i)
    {
        lev[i]=read();
        lev[i]=lev[i]*wang/wky;
    }
    for(int i=1;i<=n;++i)
    {
        int t=read();
        c[i]=read();
        w[i]=lev[t];
    }
    m=read();
    for(int i=1;i<=n;++i)
    for(int j=m;j>=w[i];--j)
    f[j]=max(f[j],f[j-w[i]]+c[i]);
    
    printf("%d\n",f[m]);
    return 0;
}