Language: C++

a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}

Compiler output:
a.cc:1:1: error: 'a' does not name a type
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      | ^
a.cc:1:9: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |         ^~~~
a.cc: In function 'int main()':
a.cc:1:32: error: 'a' was not declared in this scope
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |                                ^
a.cc:1:35: error: 'b' was not declared in this scope
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |                                   ^
a.cc:1:38: error: 'c' was not declared in this scope
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |                                      ^
a.cc:1:16: error: 'scanf' was not declared in this scope
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |                ^~~~~
a.cc:1:49: error: 'd' was not declared in this scope
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |                                                 ^
a.cc:1:61: error: 'd' was not declared in this scope
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |                                                             ^
a.cc:1:73: error: 'd' was not declared in this scope
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |                                                                         ^
a.cc:1:97: error: 'd' was not declared in this scope
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |                                                                                                 ^
a.cc:1:115: error: 'd' was not declared in this scope
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |                                                                                                                   ^
a.cc:1:101: error: 'printf' was not declared in this scope
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}
      |                                                                                                     ^~~~~~
a.cc:1:1: note: 'printf' is defined in header '<cstdio>'; this is probably fixable by adding '#include <cstdio>'
  +++ |+#include <cstdio>
    1 | a,b,c,d;main(){scanf("%d%d%d",&a,&b,&c);if(a!=b)d++;if(b!=c)d++;if(c!=a)d++;if(a==b&&b==c&&c==a)d++;printf("%d\n",d);}