using System.Collections.Immutable;

public class Solution {
    private record Time(int hours, int minutes) {
        public int Normalized { get => hours * 60 + minutes; }

        public static int Distance(Time a, Time b) =>
            Math.Abs(b.Normalized - a.Normalized);

        public static bool TryParse(string? s, out Time time) {
            if (s == null) {
                goto TimeFailedTryParse;
            }

            var parts = s.Split(":");
            if (parts.Length != 2) {
                goto TimeFailedTryParse;
            }

            if (int.TryParse(parts[0], out var hours) && int.TryParse(parts[1], out var minutes)) {
                time = new Time(hours, minutes);
                return true;
            }

TimeFailedTryParse:
            time = new Time(0, 0);
            return false;
        }
    }

    public int FindMinDifference(IList<string> timePoints) {
        var times = timePoints.Select(t => {
            Time.TryParse(t, out var time);
            return time;
        }).OrderBy(time => time.Normalized).ToImmutableList();

        return Math.Min(
            24 * 60 - Time.Distance(times.Last(), times.First()),
            times.Zip(times.Skip(1)).Select(pair => Time.Distance(pair.First, pair.Second)).Min()
        );
    }
}