View Compilation Error

0_0_23396773_5522.cpp:1:1: error: 'var' does not name a type
 var a,b:longint; begin read(a,b);writeln(a-b);end.
 ^
0_0_23396773_5522.cpp:1:18: error: 'begin' does not name a type
 var a,b:longint; begin read(a,b);writeln(a-b);end.
                  ^
0_0_23396773_5522.cpp:1:41: error: expected constructor, destructor, or type conversion before '(' token
 var a,b:longint; begin read(a,b);writeln(a-b);end.
                                         ^
0_0_23396773_5522.cpp:1:47: error: 'end' does not name a type
 var a,b:longint; begin read(a,b);writeln(a-b);end.
                                               ^