#include <iostream>
#include <cmath>
#include <string>
#include <vector>
using namespace std;
int main(){
    string rec;
    int resenje=1;
    while (cin>>rec){
        for(int i=0;i<rec.length();i++){
            if(rec[i]>='0'&&rec[i]<='9'){
                resenje=resenje*(rec[i]-'0');
            }

        }
    }
    cout << resenje << endl;
    return 0;

}