//#include<bits/stdc++.h>
#include<iostream>
#include<math.h>
#include<cstring>
#include<string.h>
#include<algorithm>
#include<stdio.h>
using namespace std;
char s1[2000],s2[2000];
int a[2000],b[2000],c[2000],n;
int la,lb;
int lc;
int main()
{
	cin>>n;
	cin>>s1;
	cin>>s2;
	la=strlen(s1);
	lb=strlen(s2);
	for(int i=0;i<la;i++)
	{
		if(s1[i]>='0'&&s1[i]<='9')a[la-i-1]=s1[i]-'0';
		else a[la-i-1]=s1[i]-'A'+10;
	}
	for(int i=0;i<lb;i++)
	{
		if(s2[i]>='0'&&s2[i]<='9')b[lb-i-1]=s2[i]-'0';
		else b[lb-i-1]=s2[i]-'A'+10;
	}
	lc=max(la,lb)+1;
	for(int i=0;i<lc;i++)
	{
		c[i]=a[i]+b[i];
		c[i+1]+=c[i]/n;
		c[i]%=n;
	}
	while(c[lc]!=0)lc++;
	for(int i=lc-1;i>=0;i--)
	{
		if(c[i]>=0 && c[i]<=9)cout<<c[i];
		else cout<<char(c[i]+'A'-10);
	}
	return 0;
}