Date.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Date
    {
        private int day;
        private int month;
        private int year;
        public Date(int day, int month, int year)
        {
            this.day = day;
            this.month = month;
            this.year = year;
        }
        public int GetYear()
        {
            return this.year;
        }
        public int GetMonth()
        {
            return this.month;
        }
        public int GetDay()
        {
            return this.day;
        }
        public int DaysInYear()
        {
            if (this.year % 4 == 0)
                return 366;
            else
                return 365;
        }
        public bool IsInteresting()
        {
            bool ans;
            bool oneDigit = this.day / 10 == 0;
            if (oneDigit)
                ans = this.day == this.year % 10;
            else
                ans = this.day == this.year % 100;
            return this.day == this.month && ans == true;
        }
        public int DaysPass()
        {
            int num = (this.month - 1) * 31 + this.day;
            if (this.month > 2)
            {
                num = num - 2;
                if (this.year % 4 != 0)
                    num = num - 1;
            }
            if (this.month > 4) num = num - 1;
            if (this.month > 6) num = num - 1;
            if (this.month > 9) num = num - 1;
            if (this.month > 11) num = num - 1;
            return num;
        }
        public string ToString()
        {
            return this.day + "/" + this.month + "/" + this.year;
        }
    }
}

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//#7
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int j = 0;
            for (int i = 0; i < 20; i++)
            {
                Date d1 = new Date(int.Parse(Console.ReadLine()), int.Parse(Console.ReadLine()), int.Parse(Console.ReadLine()));
                if (d1.IsInteresting())
                    j++;
            }
            Console.WriteLine(j);
        }
    }
}
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//#8
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            int daysSum = 0;
            while (daysSum < 400)
            {
                Date d1 = new Date(int.Parse(Console.ReadLine()), int.Parse(Console.ReadLine()), int.Parse(Console.ReadLine()));
                daysSum += d1.DaysPass();
            }
            Console.WriteLine(daysSum);
        }
    }
}