What does this Assembly snippet output?

1.global _main
2.align 2
3_main:
4    stp x29, x30, [sp, #-16]!
5    mov w19, #65
6    mov w20, #3
7loop:
8    mov w0, w19
9    bl _putchar
10    add w19, w19, #1
11    subs w20, w20, #1
12    bne loop
13    mov w0, #10
14    bl _putchar
15    ldp x29, x30, [sp], #16
16    mov w0, #0
17    ret