N = list(range(1, int(input())+1))

cnt = 0
for n in N:
    cnt += n%2!=0
    
print(cnt/len(N)) N = list(range(1, int(input())+1)) N list(range(1, int(input())+1)) list range(1, int(input())+1) range 1 int(input())+1 int(input()) int input() input 1 cnt = 0 cnt 0 for n in N:
    cnt += n%2!=0
     n N cnt += n%2!=0 cnt n%2!=0 n%2 n 2 0 print(cnt/len(N)) print cnt/len(N) cnt len(N) len N cnt = 0 0 cnt cnt += n%2!=0 n%2!=0 cnt N = list(range(1, int(input())+1)) list(range(1, int(input())+1)) N
N = list(range(1, int(input())+1))

cnt = 0
for n in N:
    cnt += n%2!=0
    
print(cnt/len(N))