#include <iostream>
using namespace std;

int main(){
    int w, z; cin >> w >> z;
    string b; cin >> b;
    int c = (b[0]-'0')*10 + (b[2]-'0');

    int ans = w+z+ w*c/10 + z*c/10;
    cout << ans << endl;
    return 0;
}