#include<bits/stdc++.h>
using namespace std;
#define FOR(i,a,n)    for(ll i=a;i<n;i++)
#define ll long long
#define PB push_back
#define vi vector<int> 
#define vl vector<ll>
#define pi pair<int,int>
#define vp vector<pi>
#define modulo (1e9+7)
int power(long long x, ll y, ll p)		// modular exponentiation
{
    ll res = 1;     // Initialize result
	x = x % p; // Update x if it is more than or
                // equal to p
    if (x == 0) return 0; // In case x is divisible by p;
	while (y > 0)
    {
        // If y is odd, multiply x with result
        if (y & 1)
            res = (res*x) % p;
        y = y>>1; // y = y/2
        x = (x*x) % p;
    }
    return res;
}
int binarySearch(vector<int> arr, int l, int r, int x)
{
    if (r >= l) {
        int mid = l + (r - l) / 2;
        if (arr[mid] == x)
            return mid;
        if (arr[mid] > x)
            return binarySearch(arr, l, mid - 1, x);
        return binarySearch(arr, mid + 1, r, x);
    }
    return -1;
}
int search1(vi arr, int n, int x)			// linear search
{
    int i;
    for (i = 0; i < n; i++)
        if (arr[i] == x)
            return i;
    return -1;
}

int main()
{
	int a,b;
    cin>>a>>b;
    int c=a*b;
    cout<<c/100;
    if(c%100!=0)
    {
        cout<<"."<<(c%100)/10;
        if(c%10!=0)
        cout<<(c%10);
    }
	return 0;
}
#include <iostream>
#include <iomanip>
using namespace std;

int main() {
  int A, B;
  cin >> A >> B;
  // std::fixed -> 固定小数点で出力することを指定
  // std::setprecision(int n) -> 小数点以下 n 桁で出力することを指定
  cout << scientific << setprecision(7);
  cout << A * B / 100.0 << '\n';
  return 0;
}
