/in/foo.c:3:5: warning: first argument of 'main' should be 'int' [-Wmain]
 int main(char* s)
     ^~~~
/in/foo.c:3:5: warning: 'main' takes only zero or two arguments [-Wmain]
/in/foo.c: In function 'main':
/in/foo.c:7:22: error: expected expression before ')' token
   result += (i+1)*(i+);
                      ^