#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
using namespace std;
int Change_num(string n,int jz1);
void Change_res(int num,int jz2);
int main()
{
    int jz1,jz2;
    string n;
    cin>>jz1;
    getchar();
    getline(cin,n);
    cin>>jz2;
    int a=Change_num(n,jz1);
    Change_res(a,jz2); 
    return 0;
}
int Change_num(string n,int jz1)
{
    int count=20,i=0,j=1,sum=0,weight[10000];
    weight[0]=1;
    while(count--)
    {
        weight[j]=jz1*weight[i];
        j++,i++;
    }
    
    i=0;
    int len=n.size();
    while(len)
    { 
        if(n.back()>='A')
        {
            int b=(int)n.back()-55;
            sum=sum+b*weight[i];
        }
        else
            sum=sum+(n.back()-'0')*weight[i];
        n.pop_back();
        i++,len--;
    }
    return sum;
}
void Change_res(int num,int jz2)
{
	int res[10000],i=0;
	while(num!=0)
	{
		res[i]=num%jz2;
		i++;
		num=num/jz2;
	}
	i--;
	while(i>=0)
	{
		if(res[i]<10)
			cout<<res[i];
		else
			cout<<(char)('A'+res[i]-10);
		i--;	
	}
}