Example:

#include <stdio.h>

int main(void){
	printf("Hello world");
	return 0;

Output

prog.c: In function ‘main’:
prog.c:5:2: error: expected declaration or statement at end of input
  return 0;
  ^~~~~~

In this program, closing brace of the main() block is missing

How to fix?

To fix this and such errors, please take care of curly braces, they are properly opened and closed.

Correct code:

#include <stdio.h>

int main(void){
	printf("Hello world");
	return 0;
}

Output

Hello world