const std = @import("std");

pub fn main() !void {
    const stdin = std.io.getStdIn();
    var buf_io = std.io.bufferedReader(stdin.reader());
    var reader = buf_io.reader();

    var buf = [_]u8{0} ** 1024;
    var total: usize = 0;
    while (try reader.readUntilDelimiterOrEof(&buf, '\n')) |line| {
        const trimmed = std.mem.trim(u8, line, " \n\r\x00");
        if (is_nice(trimmed)) {
            total += 1;
        }
    }

    std.debug.print("{}", .{total});
}

fn is_nice(s: []const u8) bool {
    var has_repeating = false;
    var has_semi_consecutive: bool = false;

    var last_letter: u8 = '_';
    var letter_even_before: u8 = '_';
    for (s, 0..) |c, i| {
        if (c == letter_even_before) {
            has_semi_consecutive = true;
        }
        if (i > 1 and std.mem.indexOf(u8, s, &[2]u8{ last_letter, c }).? < i - 2) {
            has_repeating = true;
        }
        letter_even_before = last_letter;
        last_letter = c;
    }

    return has_repeating and has_semi_consecutive;
}

test "day-tests" {
    try std.testing.expectEqual(true, is_nice("qjhvhtzxzqqjkmpb"));
    try std.testing.expectEqual(true, is_nice("xxyxx"));
    try std.testing.expectEqual(false, is_nice("uurcxstgmygtbstg"));
    try std.testing.expectEqual(false, is_nice("ieodomkazucvgmuy"));
}

test "custom-test" {
    try std.testing.expectEqual(false, is_nice("aaa"));
    try std.testing.expectEqual(true, is_nice("aaaa"));
}