View Compilation Error

0_0_22629733_2520.cpp:4:7: error: 'b' has not been declared
 int a,b;
       ^
0_0_22629733_2520.cpp:4:8: error: expected ')' before ';' token
 int a,b;
        ^
0_0_22629733_2520.cpp:4:8: error: 'main' declared as function returning a function
0_0_22629733_2520.cpp:5:6: error: expected constructor, destructor, or type conversion before '(' token
 scanf("%d%d",&a,&b);
      ^
0_0_22629733_2520.cpp:6:6: error: expected constructor, destructor, or type conversion before '(' token
 which(printf("%d\n",a+b)!EOF)
      ^
0_0_22629733_2520.cpp:8:1: error: expected unqualified-id before ')' token
 )
 ^