/*
ID: hedichehaidar
TASK: photo
LANG: C++11
*/

#include<bits/stdc++.h>
typedef long long ll;
ll gcd(ll a , ll b) {return b ? gcd(b , a % b) : a ;} // greatest common divisor (PGCD)
ll lcm(ll a , ll b) {return (a * b) / gcd(a , b);} // least common multiple (PPCM)
#define ss second
#define ff first
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define vi vector<int>
#define vii vector<pair<int,int>>
#define vl vector<ll>
#define vll vector<pair<ll,ll>>
#define pii pair<int,int>
#define pll pair<ll,ll>

using namespace std;

const int INF = 1000*1000*1000; // 1 e 9
const int MOD = INF + 7;
const double EPS = 0.000000001; // 1 e -9
const ll inf = (ll)1e18;
ll powe(ll u , ll v , ll mod = MOD){
    ll acc = u;
    ll res = 1;
    while(v){
        if(v % 2){
            res = (res * acc)%mod;
        }
        v /= 2;
        acc = (acc * acc)%mod;
    }
    return res;
}

int main() {
    //ifstream fin ("race.in");
    //ofstream fout ("race.out");
    //ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int x , y ; cin>>x>>y;
    double res = ((double)(x - y) / x) * 100;
    printf("%.9f\n" , res);
    return 0;
}




#include <stdio.h>
#include <iostream>
#include <vector>
// #include <bits/stdc++.h>
#include <queue>
#include <algorithm>
#include <string>
#include <iomanip>
#include <cmath>

using namespace std;
typedef long long ll;

#define rep(i,k,n) for(ll i=k; i<(ll)(n); i++)


int main() {
    double a,b; cin >> a >> b;

    cout << std::fixed << std::setprecision(15) << (a-b)*100/a << endl;

    return 0;
}
