View Compilation Error

0_0_39887716_3276.cpp: In function 'int main()':
0_0_39887716_3276.cpp:5:11: error: a function-definition is not allowed here before '{' token
    5 | void pre(){
      |           ^
0_0_39887716_3276.cpp:11:11: error: a function-definition is not allowed here before '{' token
   11 | int main(){
      |           ^
0_0_39887716_3276.cpp:20:2: error: expected '}' at end of input
   20 | }
      |  ^
0_0_39887716_3276.cpp:3:11: note: to match this '{'
    3 | int main(){
      |           ^