#Day number, month, year
date = [366, 1, 1901]

Month = {
    1:31,
    2:28,
    3:31,
    4:30,
    5:31,
    6:30,
    7:31,
    8:31,
    9:30,
    10:31,
    11:30,
    12:31
}

result = 0

while date[2]<=2000:
    date[1]=1
    Month[2]=28

    if date[2]%4==0:
        if date[2]%100==0 and date[2]%400!=0:
            print("special: " + str(date[2]))
            break
        Month[2]=29

    for i in range(1,13):
        
        date [0]+=Month[i]
        if date[0]%7==0:
            result+=1
    date[2]+=1

print(result)