/in/foo.c: In function 'main':
/in/foo.c:4:2: warning: statement with no effect [-Wunused-value]
 {120
  ^~~
/in/foo.c:5:5: error: expected ';' before 'printf'
     printf("hello, world\n");
     ^~~~~~
/in/foo.c: At top level:
/in/foo.c:6:2: error: expected identifier or '(' before numeric constant
 }21
  ^~