题解

题解：

#include<bits/stdc++.h>
using namespace std;
int main(){
    double h,r,a,b;
	double pi = 3.14159;
	int w = 20000;
	cin>>h>>r;
	a = pi * r * r * h;
	b = w / a;
	cout<<ceil(b);
    return 0;
}