/in/foo.c:2:6: warning: return type of 'main' is not 'int' [-Wmain]
 void main()
      ^~~~
/in/foo.c: In function 'main':
/in/foo.c:6:10: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int' [-Wformat=]
  scanf("%d%d%d",a ,b ,c);
          ^
/in/foo.c:6:12: warning: format '%d' expects argument of type 'int *', but argument 3 has type 'int' [-Wformat=]
  scanf("%d%d%d",a ,b ,c);
            ^
/in/foo.c:6:14: warning: format '%d' expects argument of type 'int *', but argument 4 has type 'int' [-Wformat=]
  scanf("%d%d%d",a ,b ,c);
              ^
/in/foo.c:6:2: warning: 'a' is used uninitialized in this function [-Wuninitialized]
  scanf("%d%d%d",a ,b ,c);
  ^~~~~~~~~~~~~~~~~~~~~~~
/in/foo.c:6:2: warning: 'b' is used uninitialized in this function [-Wuninitialized]
/in/foo.c:6:2: warning: 'c' is used uninitialized in this function [-Wuninitialized]