#include <cstdio>

#include <cmath>

#include <complex>

using namespace std;

#define pi acos(-1)

typedef complex<double> C;

const int N = ;

char s[N],t[N];

int n,m,l,r[N],c[N];

C a[N],b[N];

void fft(C *a, int f) {

    for(int i = ; i < n; i++) if(r[i] > i) swap(a[i], a[r[i]]);

    for(int i = ; i < n; i <<= ) {

        C wn(cos(pi/i), f*sin(pi/i));

        for(int j = ; j < n; j += i<<) {

            C w = ;

            for(int k = ; k < i; k++, w *= wn) {

                C x = a[j+k], y = w*a[j+k+i];

                a[j+k] = x+y, a[j+k+i] = x-y;

            }

        }

    }

}

int main() {

    scanf("%d%s%s", &m, s, t);

    for(int i = ; i < m; i++) a[i] = s[m-i-]-'', b[i] = t[m-i-]-'';

    for(n = , m <<= ; n < m; n <<= ) l++;

    for(int i = ; i < n; i++) r[i] = (r[i>>]>>)|((i&)<<(l-));

    fft(a, ), fft(b, );

    for(int i = ; i < n; i++) a[i] *= b[i];

    fft(a, -);

    for(int i = ; i < n; i++) a[i] /= n;

    for(int i = ; i < m; i++) c[i] = (int)(a[i].real()+0.1);

    for(int i = ; i < m; i++) if(c[i] >= ) {

        c[i+] += c[i]/, c[i] %= ;

    } else if(!c[i] && i == m-) m--;

    for(int i = m-; ~i; i--) printf("%d", c[i]);

    return ;

}