import random

a_wins = 0
for i in range(10**6):
    count = 5
    while count > 0:
        b = random.choice (["dead","not dead"])  #A shoots B
        if b == "dead":
            a_wins += 1
            break
        else:
            count += -1  #wasting one chance
            if count == 0:  # If count = 0 then the A will definitly die (since we started counting from 5) hence we should leave the code
                break
            a = random.choice(["dead","not dead"])  #B shoots A
            if a == "dead":
                break  #A cannot win
            else:
                count += -1   #wasting antoher chance
print(a_wins/10**6)