'''
    What's the probability P that among c persons, there will 
    be some with the same birthday? 
'''
N = int(input("N pixels = "))
ratio = 1.
c = 0
while(c < N):    # c is the number of people/obj.
    c += 1
    ratio = ratio *(365-c+1)/365
    p = 1 - ratio
    print("i",c,"P(none), P(some)",ratio,p)
    if (p < 0.5): confusion = c+1
print("confusion limit  =", confusion)