What does this Assembly snippet output?

1.global _main
2.align 2
3_main:
4    stp x29, x30, [sp, #-16]!
5    mov w19, #0
6    mov w20, #1
7outer:
8    mov w21, #1
9inner:
10    add w19, w19, #1
11    add w21, w21, #1
12    cmp w21, #3
13    ble inner
14    add w20, w20, #1
15    cmp w20, #3
16    ble outer
17    sub sp, sp, #16
18    str x19, [sp]
19    adrp x0, fmt@PAGE
20    add x0, x0, fmt@PAGEOFF
21    bl _printf
22    add sp, sp, #16
23    ldp x29, x30, [sp], #16
24    mov w0, #0
25    ret
26.section __TEXT,__cstring
27fmt: .asciz "%d\n"