What does this Zig snippet output?

1const std = @import("std");
2pub fn main() void {
3    const arr = [_]u8{ 10, 20, 30, 40 };
4    var sum: u32 = 0;
5    for (arr[1..3]) |v| {
6        sum += v;
7    }
8    std.debug.print("{d}\n", .{sum});
9}