【CodeForces 625A】Guest From the Past

#include<cstdio>
unsigned long long n,a,b,c,ans;
int main(){
    scanf("%lld%lld%lld%lld",&n,&a,&b,&c);
    if(b-c<a && n>=b){
        ans=(n-b)/(b-c)+1;
        n-=(b-c)*ans;
    }
    ans+=n/a;
    printf("%lld",ans);
    return 0;
}