#include <bits/stdc++.h>
#define rep(i,n)for(int i=0;i<(n);i++)
using namespace std;

int main(){
	int x;double p;cin>>x>>p;p/=100;
	if(x%2)printf("%.12lf\n",(x/2)*(1/p)*p+(x/2+1)*(1/p)*(1-p)+1);
	else printf("%.12lf\n",(x/2)*(1/p));
}