#region Header
#!/usr/bin/env python3
# from typing import *

import sys
import io
import math
import collections
import decimal
import itertools
from queue import PriorityQueue
import bisect
import heapq

def input():
    return sys.stdin.readline()[:-1]

sys.setrecursionlimit(1000000)
#endregion

# _INPUT = """# paste here...
# """
# sys.stdin = io.StringIO(_INPUT)


def main():
    A, B, K = map(int, input().split())
    s = set()
    for i in range(1, K+1):
        s.add(A*i)
        s.add(B*i)
    v = sorted(list(s))[K-1]
    print(v)

if __name__ == '__main__':
    main()