adzo261

n=600851475143
i=2
ans=0
while i*i<=n:
    while n%i==0:
        n//=i
        ans=i
    i=i+(1 if i==2 else 2)
if n!=1:
    ans=n

adzo261

n=600851475143
ans=0
i=2
while i<=n:
    while n % i == 0:
        n //= i
        ans = i
    i+=1
print(ans)

adzo261

a=2
b=8
sum=0
while a<4000000:
    sum += a
    a,b=b,4*b+a
print(sum)

adzo261

a=1
b=2
sum=0
while a<4000000:
    a,b=b,a+b
    if a%2==0:
        sum+=a
print(sum)

adzo261

def sum_of_multiples(n,r):
    return n*(r*(r+1))//2

print(sum_of_multiples(5,999//5)+sum_of_multiples(3,999//3)-sum_of_multiples(15,999//15))

adzo261

print(sum(i for i in range(1,1000) if i%3 ==0 or i%5==0))

adzo261

sum=0
for i in range(1,1000):
    if i%3==0 or i%5==0:
        sum+=i
print(sum)