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

typedef long long ll;
typedef vector< int > vi;
typedef vector< vi > vvi;
typedef vector< ll > vl;
typedef vector< vl > vvl;
typedef pair< int, int > pii;
typedef vector< pii > vp;
typedef vector< double > vd;
typedef vector< vd > vvd;
typedef vector< string > vs;

template< class T1, class T2 >
int upmin( T1 &x, T2 v ){
  if( x > v ){
    x = v;
    return 1;
  }
  return 0;
}

template< class T1, class T2 >
int upmax( T1 &x, T2 v ){
  if( x < v ){
    x = v;
    return 1;
  }
  return 0;
}

const int INF = 0x3f3f3f3f;

double P0, Q;

void init(){
  cin >> P0 >> Q;
}

const int T = 20;

double dp[ T ][ 1 << T ];

void preprocess(){
  P0 /= 100.0;
  Q /= 100.0;
  dp[ 1 ][ 0 ] = 1.0 / 3.0;
  for( int i = 1; i + 1 < T; ++i )
    for( int j = 0; j < 1 << i; ++j ){
      double skill = P0;
      for( int k = 1; k < i; ++k ){
        if( j & 1 << k )
          skill = min( 1.0, max( 0.0, skill - Q ) );
        else
          skill = min( 1.0, max( 0.0, skill + Q ) );
      }
      dp[ i + 1 ][ j | 1 << i ] += dp[ i ][ j ] * skill * 0.5;
      dp[ i + 1 ][ j ] += dp[ i ][ j ] * ( 1.0 - skill ) / 3.0;
    }
}

void solve(){
  double ans = 1.0 / 3.0;
  for( int i = 1; i < T; ++i )
    for( int j = 0; j < 1 << i; ++j ){
      double skill = P0;
      for( int k = 1; k < i; ++k ){
        if( j & 1 << k )
          skill = min( 1.0, max( 0.0, skill - Q ) );
        else
          skill = min( 1.0, max( 0.0, skill + Q ) );
      }
      ans += dp[ i ][ j ] * skill * 0.5;
      ans += dp[ i ][ j ] * ( 1.0 - skill ) / 3.0;
    }
  cout << fixed << setprecision( 9 ) << ans << endl;
}

signed main(){
  ios::sync_with_stdio( 0 );
  init();
  preprocess();
  solve();
  return 0;
}