2MULT HSGTPHCM L9 2016-2017

#define task "2MULT"

#include <iostream>
#include <cstdio>

using namespace std;

using ll = long long;
using ld = long double;

constexpr int N = 1e5 + 5;
string A, B;

void Read()
{
    cin >> A >> B;
}

void Solve()
{
    int ans(0);

    for(auto i : A)
        for(auto j : B)
            ans = ans + (i - '0') * (j - '0');

    cout << ans;
}

int32_t main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen(task ".INP", "r"))
    {
        freopen(task ".INP", "r", stdin);
        freopen(task ".OUT", "w", stdout);
    }

    Read();
    Solve();
}