What does this Zig snippet output?

1const std = @import("std");
2fn countDown(n: i32) i32 {
3    if (n <= 0) return 0;
4    return 1 + countDown(n - 1);
5}
6pub fn main() void {
7    std.debug.print("{d}\n", .{countDown(7)});
8}