Given n, a positive integer, how many positive integers less than n are relatively prime to n? Two integers a and b are relatively prime if there are no integers x > 1, y > 0, z > 0 such that a = xy and b = xz. Input There are several test cases. For each test case, standard input contains a line with n ≤ 1, 000, 000, 000. A line containing ‘0’ follows the last case. Output For each test case there should be single line of output answering the question posed above. Sample Input 7 12 0 Sample Output 6 4