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Goldbach DivisionTime Limit: 2000/1000 MS (Java/Others) Memory Limit: 131072/65536 K (Java/Others)Total Submission(s): 1623 Accepted Submission(s): 555 Problem Description Everybody knows Goldbach Conjecture! Here is one edition of it: 1) Every odd integer greater than 17 can be written as three different odd primes’ sum; 2) Every even integer greater than 6 can be written as two different odd primes’ sum. Loving the magical math conjecture very much, iSea try to have a closer look on it. Now he has a new definition: Goldbach Division. If we express an even integer as two different odd primes’ sum, or odd integer as three different odd primes’ sum, we call it a form of Goldbach Division of N, using a symbol G(N). For example, if N = 18, there are two ways to divide N. 18 = 5 + 13 = 7 + 11 If N = 19, there is only one way to divide N. 19 = 3 + 5 + 11 Here comes your task, give a integer N, find |G(N)|, the number of different G(N). Input There are several test cases in the input. Each test case includes one integer N (1 <= N <= 20000). The input terminates by end of file marker. Output For each test case, output one integer, indicating |G(N)|. Sample Input
Sample Output
Hint There may be 2000 cases, be careful. Author iSea @ WHU Source | ||||||||||
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