using System;

public class Program

{

    public void Main()

    {

        int referenceSunday = 14; // 14 January 1900 was the second Sunday of 1900

        // every year, that Sunday will move by netChange days. Actaully, 

        // -1 -> 364-365 (which is 7* Math.Truncate(days_current_year/7)-days_current_year) on non-leap years

        // -2 -> 364-366 (same formula) on leap years

        int count=0;

        int thisYearCount;

        for (int i=1901;i<2001;i++){ // for the year from the 

            thisYearCount=1; //counting reference Sunday

            if(isLeapYear(i-1)) referenceSunday-=2; 

            else referenceSunday-=1;

            if(referenceSunday<7) referenceSunday+=7; //preventing the reference going too much backward

            for(int j=1;j<5;j++){

                if(referenceSunday-j*7>0){ 

                     thisYearCount++; // counting Sundays before reference

                }

                else break;

            }

            for(int j=1;j<5;j++){

                if(referenceSunday+j*7<32) thisYearCount++; // counting Sundays after reference

                else break;

            }

            count+=thisYearCount;

            Console.WriteLine("reference Sunday of Year "+i+" is "+referenceSunday+" count: "+thisYearCount);

        }

        Console.WriteLine(count);

    }

    public bool isLeapYear(int year){

        if(year%4!=0)return false;

        if(year%100!=0)return true;

        if(year%400!=0)return false;

        return true;

    }

}