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

#define INF_LL (int64)1e18
#define INF (int32)1e9
#define REP(i, n) for(int i = 0;i < (n);i++)
#define FOR(i, a, b) for(int i = (a);i < (b);i++)
#define all(x) x.begin(),x.end()
#define fs first
#define sc second

using int32 = int_fast32_t;
using uint32 = uint_fast32_t;
using int64 = int_fast64_t;
using uint64 = uint_fast64_t;
using PII = pair<int32, int32>;
using PLL = pair<int64, int64>;

const double eps = 1e-6;

template<typename A, typename B>inline void chmin(A &a, B b){if(a > b) a = b;}
template<typename A, typename B>inline void chmax(A &a, B b){if(a < b) a = b;}

const int64 mod = 1e9+7;

double res = 0;
double P;

double E(int64 x){
	double num = 1/P;
	return num*x/2;
}

int main(void){
	int64 x;
	cin >> x >> P;
	P /= 100;
	if(x%2){
		res = 1;
		res += E(x-1)*P;
		res += E(x+1)*(1-P);
	}else{
		res += E(x);
	}
	cout << fixed << setprecision(10) << res << endl;
}