#!/usr/local/bin/python3.5 -u

count = 0
i = 2
while i < 100:
    k = i / 2
    j = 2
    while j <= k:
        k = i % j
        if k == 0:
            count = count - 1
            break
        k = i / 2
        j = j + 1
    count = count + 1
    i = i + 1
print(count)

