What does this Zig snippet output?

1const std = @import("std");
2pub fn main() void {
3    const matrix = [2][3]u8{
4        .{ 1, 2, 3 },
5        .{ 4, 5, 6 },
6    };
7    std.debug.print("{d}\n", .{matrix[1][2]});
8}