from copy import deepcopy

A = int( input() )
P = list( map( lambda x: int( x ) / 100, input().split() ) )

dp = [ 0.0 for i in range( 2 ) ]
dp = [ deepcopy( dp ) for i in range( 14 + 1 ) ]
dp = [ deepcopy( dp ) for i in range( 80 - A + 1 ) ]
for i in range( 1, 14 + 1 ):
  for j in range( 2 ):
    dp[ 0 ][ i ][ j ] = i

for i in range( 1, 80 - A + 1 ): # 何年たつ
  for j in range( 1, 14 + 1 ): # いくつ歯が残る
    for k in range( 2 ): # 最初の歯の左に歯がある
      if j == 1:
        dp[ i ][ j ][ k ] = ( 1 - P[ k ] ) * dp[ i - 1 ][ j ][ 0 ]
      else:
        all_alive = 1.0
        for x in range( j ): # 最初に壊れる歯
          i_die = P[ 1 ] if ( ( x == 0 and k == 0 ) or x + 1 == j ) else P[ 2 ]
          dp[ i ][ j ][ k ] += all_alive * i_die * ( dp[ i - 1 ][ x ][ 0 ] + dp[ i ][ j - x - 1 ][ 1 ] )
          all_alive *= 1 - i_die
        dp[ i ][ j ][ k ] += all_alive * dp[ i - 1 ][ j ][ 0 ]

print( "%.7f" % ( dp[ 80 - A ][ 14 ][ 0 ] * 2 ) )