#include<iostream>
using ll = long long;
using namespace std;
int main(){
    ll a,b;
    ll ans;
    cin >> a >> b;
    ans = a*b;
    if(a%10==0&&b%10==0)    cout << ans/10;
    else if(ans >= -99999999 && ans <= 99999999) cout << ans;
    else    cout << "E\n";
    return 0;
}