出错在第三个样例

#include<iostream>
void sum(int n,int k,int &ret);
using namespace std;
int main(){
	int n,k;
	int ret=0;
	cin>>n>>k;
	sum(n,k,ret);
	cout<<ret<<endl;
}
void sum(int n,int k,int &ret){
    ret+=n;
	while(n!=0)	{
	return sum(n/k,k,ret);
    }	
}