#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    string s;
    ll t;
    cin >> s >> t;
    rep(i,6)s[i] -= '0';
    ll v = s[2]*1000 + s[3]*100 + s[4]*10 + s[5];
    ll ans = v * t / 10000;
    cout << ans << endl;
    return 0;
}