prog.cs(21,1): error CS0103: The name `Sum' does not exist in the current context
prog.cs(22,12): error CS0019: Operator `<' cannot be applied to operands of type `int' and `int[]'
prog.cs(23,8): error CS0103: The name `Sum' does not exist in the current context
prog.cs(23,2): error CS0103: The name `Sum' does not exist in the current context
Compilation failed: 4 error(s), 0 warnings