program example {
               declarations
               a -> Integer;
               b -> Integer;
               c -> Integer;
               subProgram sum(x -> Integer,y -> Integer) -> Integer {
                                                                   declarations
                                                                   b -> Boolean;
                                                                   
statements
                                                                   if((x + 1) == y) then  {
                                                                                         write 1000;
                                                                                          }
                                                                                    else  {
                                                                                         skip;
                                                                                          }
                                                                   ;
                                                                   return (x + y);
                                                                    };
               
statements
               read a;
               read b;
               c := (2 * sum(a,b));
               write c;
                }