a,b,k = map(int,input().split())
t = []
for i in range(1,100+1):
    if a % i == 0 and b % i == 0:
        t.append(i)
t.sort(reverse=True)
print(t[k-1]) a,b,k = map(int,input().split()) a map(int,input().split()) map int input().split() ().split () input split b k t = [] t [] for i in range(1,100+1):
    if a % i == 0 and b % i == 0:
        t.append(i) i range(1,100+1) range 1 100+1 100 1 if a % i == 0 and b % i == 0:
        t.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 t.append(i) t.append t append i t.sort(reverse=True) t.sort t sort reverse=True reverse True print(t[k-1]) print t[k-1] t k-1 k 1 k = map(int,input().split()) map(int,input().split()) k a,b,k = map(int,input().split()) map(int,input().split()) a t = [] [] t b,k = map(int,input().split()) map(int,input().split()) b
a,b,k = map(int,input().split())
t = []
for i in range(1,100+1):
    if a % i == 0 and b % i == 0:
        t.append(i)
t.sort(reverse=True)
print(t[k-1])