View Compilation Error

0_0_18849166_2155.cpp: In function 'void gcdEx(int, int, int&, int&)':
0_0_18849166_2155.cpp:12:11: error: a function-definition is not allowed here before '{' token
 int main(){
           ^
0_0_18849166_2155.cpp:36:1: error: expected '}' at end of input
 }
 ^