#include<set>

#include<map>

#include<ctime>

#include<queue>

#include<cmath>

#include<cstdio>

#include<vector>

#include<cstring>

#include<cstdlib>

#include<complex>

#include<iostream>

#include<algorithm>

#define maxn 131073

#define pi acos(-1)

using namespace std;

typedef complex<double> E;

int n,m,r[maxn],l=,c[maxn];

char s[maxn];

E a[maxn],b[maxn];

void fft(E *x,int f)

{

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

        if (i<r[i]) swap(x[i],x[r[i]]);

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

    {

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

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

        {

            E w(,);

            for (int k=;k<i;k++)

            {

                E r1,r2;

                r1=x[j+k];r2=w*x[i+j+k];

                x[j+k]=r1+r2;x[j+k+i]=r1-r2;

                w*=wn;

            }

        }

    }

    if (f==-)

    {

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

            x[i]/=n;

    }

}

int main()

{

    scanf("%d",&n);n--;

    scanf("%s",s);for (int i=;i<=n;i++) a[i]=s[n-i]-'';

    scanf("%s",s);for (int i=;i<=n;i++) b[i]=s[n-i]-'';

    m=*n;

    for (n=;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<=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]%=;

            if (i==m) m++;

        }

    }

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

    printf("\n");

    return ;

}