#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define rep(i, n) for(int i=0; i<(int)(n); i++)

double A, B;

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    cin >> A >> B;
    cout << A*B/100 << endl;
}
                              ////JAI SHREE RAM////
#include <iostream>
#include<bits/stdc++.h>
#include <math.h>
using namespace std;
const long long int INF = (long long)1e15;
const long long int mod = 1e9+7;
#define ll long long
#define f(i,a,b) for(int i=a;i<b;i++)
#define pb push_back
#define all(c) c.begin(),c.end()
#define rall(c) c.rbegin(),c.rend()
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define sd second
#define ft first

bool cmp(const pair<int,int> &a, const pair<int,int> &b)
{
    //return (a.sd>=b.sd);
    return abs(a.ft)+abs(a.sd) < abs(b.ft)+abs(b.sd);
}
void prime(vector<ll>&v,ll n)
{
    for(ll i=2;i*i<=n;i++)
    {
        if(n%i==0)
        {
            v.pb(i);
            if(n/i!=i) v.pb(n/i);
        }
    }
    v.pb(n);
}
int binPow(int a, int n)
{
    int res=1;
    while(n)
    {
        if(n&1)
            res=(1ll*res*a)%mod;
        a=(1ll*a*a)%mod;
        n>>=1;
    }
    return res;
}
int C(int n,int k,ll fact[],ll inv[])
{
    if(k>n) return 0;
    int res = (1ll*fact[n]*inv[k])%mod;
    res=(1ll*res*inv[n-k])%mod;
    //cout<<res<<endl;
    return res;
}

void solve()
{
    double a,b;cin>>a>>b;
    double ans = (a*b)/100;
    cout<<setprecision(12)<<ans<<endl;
}
int main()
{
    //ios_base::sync_with_stdio(false); cin.tie(0);cout.tie(0);
    int t=1;
    //cin>>t;

    while(t--)
    {
        solve();
    }
    return 0;
}

