#include <bits/stdc++.h>
#include <assert.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define PB push_back
#define MP make_pair
#define MOD 1000000007LL
#define endl "\n"
const ll UNDEF = -1;
const ll INF=1e18;
template<typename T> inline bool chkmax(T &aa, T bb) { return aa < bb ? aa = bb, true : false; }
template<typename T> inline bool chkmin(T &aa, T bb) { return aa > bb ? aa = bb, true : false; }
typedef pair<ll,ll> pll;

#ifdef DEBUG
     #define debug(args...)            {dbg,args; cerr<<endl;}
#else
    #define debug(args...)              // Just strip off all debug tokens
#endif

struct debugger
{
    template<typename T> debugger& operator , (const T& v)
    {    
        cerr<<v<<" ";    
        return *this;    
    }
} dbg;
ld solve(ll b, ld p) {
	ld ans;
	if (b==0) ans=0;
	else ans=b/p;
	return ans;
}
int main()
{
	ios_base::sync_with_stdio(false); cin.tie(0);
	cout<<fixed<<setprecision(10);
	ll x,pp; cin>>x>>pp;
	ld p=(ld)pp/100.0;
	ll b=x/2;
	if (x&1) {
		ld ans=solve(1,p)+(solve(b,p));
		cout<<ans<<endl;
	}
	else {
		cout<<solve(b,p)<<endl;
	}
}

