A = int(raw_input())
P = map(lambda x: int(x) / 100. ,raw_input().split(" "))
dp = [[0 for j in range(16)] for i in range(80-A+1)]
for j in range(1,15):
	dp[0][j] = 1
for i in range(80-A):
	for j in range(1,15):
		dp[i+1][j] = dp[i][j] * (1 - (1-dp[i][j-1])*(1-dp[i][j+1])*P[0]
					  - ((1-dp[i][j-1])*dp[i][j+1] + dp[i][j-1]*(1-dp[i][j+1]))*P[1]
					  - dp[i][j-1]*dp[i][j+1]*P[2])
print sum(dp[80-A]) * 2