#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF LLONG_MAX/10
#define rep(i,n) for(int i=0;i<n;i++)
#define krep(i,k,n,m) for(int i=k;i<n;i+=m)
#define erep(i,k,n) for(int i=k;i<n;i++)
#define mod 1000000007
//最大公約数
int gcd(int s,int b){
    if(b==0)return s;
    return gcd(b,s%b);
}

signed main(){
    int a;
    double b;
    cin>>a>>b;
    a=a*b;
    cout<<a<<endl;
}
