#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("atestat.in");
ofstream fout("atestat.out");
int main()
{
    long long int d,nou=1,x;
    int ok;
    while(fin>>x)
    {
        ok=1;
        if(x<2)
            ok=0;
        for(d=2;d<x;d++)
            if(x%d==0)
                ok=0;
        if(ok==1)
            nou=nou*x;
    }
    fout<<nou;
    return 0;
}