本人蒟蒻，各位大佬轻点喷

#include<bits/stdc++.h>
using namespace std;

stack<int> s;
char arr[]="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

void dfs(int a,int b)
{
	if(a>b)
	{
		int num=a%b;
		a=a/b;
		s.push(arr[num]);
		dfs(a,b);
	}
	else
	{
		s.push(arr[a]);
	}
}

int main()
{
	int a,b;
	cin>>a>>b;
	dfs(a,b);
	while(!s.empty())
	{
		char c;
		c=s.top();
		cout<<c;
		s.pop();
	}
	return 0;
}