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FriendTime Limit: 1000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3493 Accepted Submission(s): 1820 Problem Description Friend number are defined recursively as follows. (1) numbers 1 and 2 are friend number; (2) if a and b are friend numbers, so is ab+a+b; (3) only the numbers defined in (1) and (2) are friend number. Now your task is to judge whether an integer is a friend number. Input There are several lines in input, each line has a nunnegative integer a, 0<=a<=2^30. Output For the number a on each line of the input, if a is a friend number, output “YES!”, otherwise output “NO!”. Sample Input
Sample Output
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