Ignoring the air resistance, velocity of a freely falling object $v$ after $t$ seconds and its drop $y$ in $t$ seconds are represented by the following formulas:      $ v = 9.8 t $   $ y = 4.9 t^2 $    A person is trying to drop down a glass ball and check whether it will crack. Your task is to write a program to help this experiment.  You are given the minimum velocity to crack the ball. Your program should print the lowest possible floor of a building to crack the ball. The height of the $N$ floor of the building is defined by $5 \times N - 5$.
while 1:
    try:
        y = 4.9 * (float(input()) / 9.8) ** 2
        N = 1
        while N * 5 - 5 < y:
            N += 1
        print(N)
    except:
        pass
try:
    while 1:
        y = 4.9 * (float(input()) / 9.8) ** 2
        N = 1
        while N * 5 - 5 < y:
            N += 1
        print(N)
except:
    pass