Why is my HACK ASM wrong?

//addn.asm

//This asm computes the sum of n numbers

//Assuming RAM[0] stores the value n (how many numbers to sum)

//and the numbers are stored in consecutive addresses starting at address 1.

//The result will be stored in RAM[0], overwriting the original value of n.

//It may be useful to use variables when solving this problem.

//Write your code below.

@R0

D=M

@N

M=D

@R1

D=M

@Y

M=D

// //while (i > 0){

// A = A+1

// D = D + M

// i --

// }

@i

M = 0

@sum

M=0

(loop)

//If i < 16 or if i >= 0 break the loop

@i

D=M

@C

D=D-M //i-n

@cont

D; JGE

//sum = Ram[0]

@i

D=M

@Y

A = D+M

D=M

@sum

M=D+M

@i

M=M+1

@loop

0; JMP

(cont)

@sum

D=M

@R0

M=D

(end)

@end

0;JMP