import math
def je_prvocislo(n):
    if n <= 1:
        return False
    elif n != 2 and n%2 == 0:
        return False
    for i in range(3,int(math.sqrt(n)+1),2):
        if n%i == 0:
            return False
    return True

print(je_prvocislo(1))
print(je_prvocislo(2))
print(je_prvocislo(8))
print(je_prvocislo(15))
print(je_prvocislo(11))
print(je_prvocislo(967))