#include<bits/stdc++.h>
using namespace std;
string sa,sb;
int a[2005],b[2005],c[2005],n;
int main()
{
	cin>>n>>sa>>sb;
	int lena=sa.size();
	int lenb=sb.size();
	for(int i=lena-1; i>=0; i--)
	{
		if(sa[i] >= '0' && sa[i] <= '9')
			a[lena-i-1]=sa[i]-'0';
		else
			a[lena-i-1]=sa[i]-'A'+10;
	}
	for(int i=lenb-1; i>=0; i--)
	{
		if(sb[i] >= '0' && sb[i] <= '9')
			b[lenb-i-1]=sb[i]-'0';
		else
			b[lena-i-1]=sb[i]-'A'+10;
	}
	int lenc=0;
	while(lenc < lena || lenc < lenb)
	{
		c[lenc]=a[lenc]+b[lenc]+x;
		x=c[lenc]/n;
		c[lenc]%=n;
		lenc++;
	}
	if(x != 0)
		c[lenc]=x;
	else
		lenc--;
	for(int i=lenc; i>=0; i--)
	{
		if(c[i] <= 9 && c[i] >= 0)
			cout<<c[i];
		else
			cout<<char(c[i]+55);
	}
	return 0;
}