推 TimcApple : 設 2019^8 = -1, 2019^16 = 1 (mod p) 03/07 23:47
→ TimcApple : p = 16k + 1 = 17, 97, ... 03/07 23:47
→ TimcApple : 其中 2019 = -4, 2019^4 = 1 (mod 17) 不合 03/07 23:47
→ TimcApple : 接著 2019 = -18, 2019^2 = 33 03/07 23:47
→ TimcApple : 2019^4 = 22, 2019^8 = -1 (mod 97) 03/07 23:47
→ TimcApple : 因此答案是 97 03/07 23:47