#include <bits/stdc++.h>
using namespace std;

double A, B;

int main() {
    cin >> A >> B;
    cout << fixed << setprecision(9) << (A-B) / A * 100.0 << endl;
}
//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#include <algorithm>
#define rep(i,n) for(int i=0;i<(n);++i)
#define all(a) (a).begin(),(a).end()
using namespace std;
using Graph = vector<vector<int>>;
typedef long long ll;
//using Graph = vector<vector<pair<ll,ll>>>;
const int mod =1e+9+7;

const int dy[4]={0,1,0,-1};
const int dx[4]={1,0,-1,0};

const ll INF=1e18;

int main(){
    ll a,b; cin>>a>>b;
    ll c=a+b;
    if(c>=15&&b>=8)cout<<1<<endl;
    else if(c>=10&&b>=3)cout<<2<<endl;
    else if(c>=3)cout<<3<<endl;
    else cout<<4<<endl;
}







