py(题解)

n=int(input())
if n == 1:
    print(31)
elif n ==2:
    print(28)
elif n ==3:
    print(31)
elif n ==4:
    print(30)
elif n ==5:
    print(31)
elif n ==6:
    print(30)
elif n ==7:
    print(31)
elif n ==8:
    print(31)
elif n ==9:
    print(30)
elif n ==10:
    print(31)
elif n ==11:
    print(30)
else:
    print(31)