View Compilation Error

0_0_11162462_16727.cpp:3: error: invalid function declaration
0_0_11162462_16727.cpp: In function `int prime(int)':
0_0_11162462_16727.cpp:15: error: `prime_num' undeclared (first use this function)
0_0_11162462_16727.cpp:15: error: (Each undeclared identifier is reported only once for each function it appears in.)