View Compilation Error

0_0_4576704_3690.cpp:32: error: ISO C++ forbids declaration of `__gcd' with no type
0_0_4576704_3690.cpp: In function `int __gcd(int, int)':
0_0_4576704_3690.cpp:35: error: `gcd' undeclared (first use this function)
0_0_4576704_3690.cpp:35: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4576704_3690.cpp: In function `bool canmov(int, int, int)':
0_0_4576704_3690.cpp:42: error: `gcd' undeclared (first use this function)