#include <fstream>
#include <iostream>

using namespace std;

ifstream f("multiplu.in");
ofstream g("multiplu.out");

long long a, b, rez;

bool valid(long long x)
{
    bool rez = true;
    for(; x && rez; x /= 10)
    {
        if(x%10 > 1)
            rez = false;
    }
    return rez;
}

long long calc(long long prod)
{
    int i = 1;
    for(;;)
    {
        prod *= i;
        if(valid(prod))
            break;
        else
            prod /= i, i++;
    }
    return prod;
}

int main ()
{
    f >> a >> b;
    g << calc(a * b);
}