/in/foo.c: In function 'main':
/in/foo.c:4:19: error: expected '=', ',', ';', 'asm' or '__attribute__' before ':' token
    4 |          int a,b,c:
      |                   ^
/in/foo.c:6:10: error: 'c' undeclared (first use in this function)
    6 |          c=a+b;
      |          ^
/in/foo.c:6:10: note: each undeclared identifier is reported only once for each function it appears in