/in/foo.c: In function 'main':
/in/foo.c:6:2: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'scanf'
  scanf("%d%d%d",&a,&b,&c);
  ^~~~~
/in/foo.c:10:3: error: 'max' undeclared (first use in this function)
   max=a;
   ^~~
/in/foo.c:10:3: note: each undeclared identifier is reported only once for each function it appears in