import sys
input = sys.stdin.readline


def main():
    A, B, C = map(int, input().split())
    
    left = 1
    right = 10**18 + 1
    while right - left > 1:
        mid = left + (right - left) // 2
        k = mid//A
        money = (mid - k) + k * B
        if money >= C:
            right = mid
        else:
            left = mid
    
    print(right)

if __name__ == '__main__':
    main()