What does this Zig snippet output?

1const std = @import("std");
2pub fn main() void {
3    const Pair = struct { a: i32, b: i32 };
4    const pairs = [_]Pair{
5        .{ .a = 1, .b = 10 },
6        .{ .a = 2, .b = 20 },
7        .{ .a = 3, .b = 30 },
8    };
9    var sum: i32 = 0;
10    for (pairs) |p| {
11        sum += p.b;
12    }
13    std.debug.print("{d}\n", .{sum});
14}