arrp=[]
x=8600851475143

for i in range(2,x//2):
    j=0
    for ii in range (2,i-1):
        if i%ii==0:
            j=1
            break
    if x%i==0 and j==0:
        arrp.append(i)
print(arrp)
print("answer")
print(arrp[len(arrp)-1])