#include <cstdio>#include <cmath>#include <algorithm>#define N 1 << 20#define pi acos(-1)using namespace std;struct data{	double x , y;	data() {x = y = 0;}	data(double x0 , double y0) { x = x0 , y = y0;}	data operator +(const data a)const {return data(x + a.x , y + a.y);}	data operator -(const data a)const {return data(x - a.x , y - a.y);}	data operator *(const data a)const {return data(x * a.x - y * a.y , x * a.y + y * a.x);}}a[N] , b[N] , c[N];char sa[N] , sb[N];int ans[N];void fft(data *a , int n , int flag){	int i , j , k = 0;	for(i = 0 ; i < n ; i ++ )	{		if(i > k) swap(a[i] , a[k]);		for(j = (n >> 1) ; (k ^= j) < j ; j >>= 1);	}	for(k = 2 ; k <= n ; k <<= 1)	{		data wn(cos(2 * pi * flag / k) , sin(2 * pi * flag / k));		for(i = 0 ; i <= n ; i += k)		{			data t , w(1 , 0);			for(j = 0 ; j < (k >> 1) ; j ++ , w = w * wn)			{				t = w * a[i + j + (k >> 1)];				a[i + j + (k >> 1)] = a[i + j] - t;				a[i + j] = a[i + j] + t;			}		}	}}int main(){	int n , i , len;	scanf("%d%s%s" , &n , sa + 1 , sb + 1);	for(i = n ; i > 0 ; i -- )		a[n - i].x = a[n - i].x * 10 + sa[i] - ‘0‘ , b[n - i].x = b[n - i].x * 10 + sb[i] - ‘0‘;	for(len = 1 ; len <= (n << 1) ; len <<= 1);	fft(a , len , 1) , fft(b , len , 1);	for(i = 0 ; i < len ; i ++ ) c[i] = a[i] * b[i];	fft(c , len , -1);	for(i = 0 ; i < len ; i ++ ) ans[i] = (int)((c[i].x + 0.5) / len);	for(i = 0 ; i < len ; i ++ ) ans[i + 1] += ans[i] / 10 , ans[i] %= 10;	for(i = len - 1 ; i && !ans[i] ; i -- );	for( ; ~i ; i -- ) printf("%d" , ans[i]);	printf("\n");	return 0;}