#include <cstring>
#include <iostream>
using namespace std;
int main()
{
    int n, a[101] = { 0 }, b[101] = { 0 }, c[201] = { 0 }, lena, lenb, lenc = 0;
    string a1, b1;
    cin >> n >> a1 >> b1;
    lena = a1.size();
    lenb = b1.size();
    for (int i = 0; i < lena; i++) {
        if (a1[i] >= 'A') {
            a1[i] = a1[i] - 'A' + '9' + 1;
        }
        a[lena-i-1] = a1[i] - '0';
    }
    for (int i = 0; i < lenb; i++) {
        if (b1[i] >= 'A') {
            b1[i] = b1[i] - 'A' + '9' + 1;
        }
        b[lenb-1-i] = b1[i] - '0';
    }
    for (int i = 0; i < lena; i++) {
        for (int j = 0; j < lenb; j++) {
            c[i + j] += a[i] * b[j];
            c[i + j + 1] += c[i + j] / n;
            c[i + j] %= n;
        }
    }
    int len = lena + lenb;
    while(c[len-1]==0&&len>0){
        len--;
    }
    while (len > 0) {
        --len;
        if (c[len] > 9) {
            char c1 = c[len] - 10 + 'A';
            cout << c1;
        } else {
            cout << c[len];
        }
    }
}