#include <bits/stdc++.h>
using namespace std;
int a[5050], b[5050], c[5050];
string s1, s2; 

int main() {
	int n;
	cin>>n;
	int ca, cb, cc; 
	cin >> s1 >> s2;
	ca = s1.size(); 
	cb = s2.size();
	for (int i = 0; i < ca; i++){
		if(n>10&&s1[ca-i-1]>='A') a[i]=s1[ca-i-1]-'A'+10;
		else a[i] = s1[ca-i-1]- '0'; 
	}
	for (int i = 0; i < cb; i++){
		if(n>10&&s2[cb-i-1]>='A') b[i]=s2[cb-i-1]-'A'+10;
		else a[i] = s2[cb-i-1] - '0'; 
	}
	cc = max(ca, cb) + 1; 
	for (int i = 1; i <= cc; i++) {
		c[i] += a[i] + b[i]; 
		c[i + 1] = c[i] / n; 
		c[i] = c[i] % n; 
	}
	if (c[cc] == 0 && cc > 0)
		cc--;
	for (int i = cc; i > 0; i--){
		if(c[i]<=9) cout<<c[i];
		else cout<<(char)(a[i]-10+'A');
	}
	return 0;
}