5分钟写完 水水更开心

//By SiriusRen

#include <cstdio>

#include <iostream>

#include <algorithm>

using namespace std;

int m,t,u,f,d;

char jy;

int main(){

    scanf("%d%d%d%d%d",&m,&t,&u,&f,&d);

    for(int i=1;i<=t;i++){

        cin>>jy;

        if(jy=='f'){

            if(m-2*f>=0)m-=2*f;

            else {printf("%d\n",i-1);return 0;}

        }

        if(jy=='d'||jy=='u'){

            if(m-u-d>=0)m=m-u-d;

            else {printf("%d\n",i-1);return 0;}

        }

    }

    printf("%d\n",t);

}