可以使用（#define _USE_MATH_DEFINES），也可以用#派#:3.1415926535897932384626433832795028841971693993751058209749445923078164062

#define _USE_MATH_DEFINES
#include<bits/stdc++.h>
using namespace std;
int main(){
	long long x,y,t;
	cin>>x>>y;
	t=((x*x+y*y)*M_PI/*3.1415926535897932384626433832795028841971693993751058209749445923078164062*//100);
	cout<<t;
	return 0;
}

/***************************************
Note:
***************************************/
#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <string>
#include <iomanip>
#include <cmath>
#include <queue>
#include <map>
#include <stack>
#include <vector>
#include <fstream>
using namespace std;
#define LL long long
#define ULL unsigned long long
#define ULLI unsigned long long int
const int N = 1e6+6;
const double py = 3.1415926535897932384626433832795;
int main(){
	LL x,y,t;
	cin >> x >> y;
	t = (x * x + y * y) * py / 100;
	cout << t;
    return 0;
}