超时了......求帮助

#include <iostream>

using namespace std;

int main(){
    int n=0,k=0,p=0,y=0;
    cin>>n>>k;
    y=n;
    for(;y>=k;){        
        p+=n;
        n=y/k;          //换烟
        y-=y/k; 
        y+=n;           //吸烟 
        if(y<k){
            break;
        }
    }
    cout<<p;
    return 0;
}