
a, b, k = map(int, input().split(' '))
m = min(a,b)
ans = []
for i in range(1,m+1):
    if a%i==0 and b%i==0:
        ans.append(i)
print(ans[-k]) a, b, k = map(int, input().split(' ')) a map(int, input().split(' ')) map int input().split(' ') ().split () input split ' ' b k m = min(a,b) m min(a,b) min a b ans = [] ans [] for i in range(1,m+1):
    if a%i==0 and b%i==0:
        ans.append(i) i range(1,m+1) range 1 m+1 m 1 if a%i==0 and b%i==0:
        ans.append(i) a%i==0 and b%i==0 a%i==0 a%i a i 0 b%i==0 b%i b i 0 ans.append(i) ans.append ans append i print(ans[-k]) print ans[-k] ans -k k k = map(int, input().split(' ')) map(int, input().split(' ')) k a, b, k = map(int, input().split(' ')) map(int, input().split(' ')) a b, k = map(int, input().split(' ')) map(int, input().split(' ')) b ans = [] [] ans m = min(a,b) min(a,b) m

a, b, k = map(int, input().split(' '))
m = min(a,b)
ans = []
for i in range(1,m+1):
    if a%i==0 and b%i==0:
        ans.append(i)
print(ans[-k])