\(很简单的计算题吧\)
\(上代码\)\(:\)

#include<iostream>
using namespace std;
int main(){
register unsigned int i;
int q,m,n,p,x,y,k,ans;
cin>>q>>m>>n>>p>>x>>y>>k;
for(i=n;i<=p;++i) m+=x;
//cout<<m<<endl;
if(m-(k-p)*y>q) return cout<<-1<<endl,0;
ans=p;
for(i=p;i<=k;++i){
m-=y;
++ans;
if(m<q){
break;
}
}
return cout<<ans<<endl,0;
}