//مبتسمون رغم الخرا
#include <bits/stdc++.h>
#define int long long int
#define ZaZo ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define ceil1(a,b)   (a+(b-1))/b
#define all(v)  v.begin(),v.end()
using namespace std;
int32_t main()
{
	ZaZo
	double a,b;
	cin>>a>>b;
	cout<<(double)(((a-b)/a)*(double)100);
}

#include <bits/stdc++.h>
#define ll long long int
using namespace std;
ll f=0;
ll pre[500];
ll nCr(int n, int r)
{
 
    ll p = 1, k = 1;
 
    // C(n, r) == C(n, n-r),
    // choosing the smaller value
    if (n - r < r)
        r = n - r;
 
    if (r != 0) {
        while (r) {
            p *= n;
            k *= r;
 
            // gcd of p, k
            long long m = __gcd(p, k);
            p /= m;
            k /= m;
 
            n--;
            r--;
        }
 
    }
 
    else
        p = 1;
 
 return p;
}
int main() {
    ll dp[200];
    dp[0] =1;
    ll n;
    cin>>n;
    for(ll i=1;i<200;i++)
    {
        dp[i] = dp[i-1]*11;
        // cout<<dp[i]<<endl;
    }
    // n-=12;
    ll ans =0;
    n--;
    cout<<nCr(n,11)<<endl;

}
