#include <bits/stdc++.h>

using namespace std;
int main(){
    int a, b;
    scanf("%d%d", &a, &b);
    int c = (a - b) * 100;
    double d = c * 1.0 / a;
    printf("%.20lf", d);
    return 0;
}
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
using namespace std;

#define rep(i, l, r) for(int i=(l), i##_end_=(r); i<=i##_end_; ++i)
#define drep(i, l, r) for(int i=(l), i##_end_=(r); i>=i##_end_; --i)
#define fi first
#define se second
#define mp(a, b) make_pair(a, b)
#define Endl putchar('\n')
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
template<class T>inline T fab(T x){ return x<0? -x: x; }
template<class T>inline T readin(T x){
    x=0; int f=0; char c;
    while((c=getchar())<'0' || '9'<c) if(c=='-') f=1;
    for(x=(c^48); '0'<=(c=getchar()) && c<='9'; x=(x<<1)+(x<<3)+(c^48));
    return f? -x: x;
}

int a, b;

signed main(){
    a=readin(1), b=readin(1);
    b=a-b;
    printf("%.15f\n", b*100.0/a);
    return 0;
}