#include<iostream>
#include<algorithm>
#include<iomanip>
using namespace std;
int main()
{
double a,b;
cin>>a>>b;
cout<<100*(1-(b/a));
return 0;
}
#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()
#define print(x) cout << (x) << endl
typedef long long ll;
const ll MOD = 1000000007;
const ll MOD2 = 998244353;
 
using namespace std;
using Graph = vector<vector<int>>;

int main(){
    ll n, k;   cin >> n >> k;
    ll ans = 0;
    k = abs(k);
    for(int i=k+2; i<=2*n; i++){
        ll tmp;
        if(i > n + 1) tmp = 2*n - i + 1;
        else    tmp = i - 1;
        if(i - k > n + 1) tmp *= (2*n - (i - k) + 1);
        else    tmp *= (i - k - 1);
        ans += tmp;
    }
    print(ans);
}