// yukicoder: No.604 誕生日のお小遣い
// 2019.4.20 bal4u

#include <stdio.h>

typedef long long ll;
typedef __int128_t Bint;  // GCC 環境下でないと動かないかも

int getchar_unlocked(void);
#define gc() getchar_unlocked()

ll in() {   // 非負整数の入力
	ll n = 0; int c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

ll A, B, C;

#define calc(x) ((Bint)(x)/A*B + (x-x/A)) 
	
ll bsch(ll x)
{
	ll l = 1, r = x;

	while (l+1 < r) {
		ll m = l + ((r-l) >> 1);
		if (calc(m) >= C) r = m; else l = m;
	}
	return r;
}

int main()
{
	A = in(), B = in(), C = in();
	if (calc(1) >= C) puts("1");
	else printf("%lld\n", bsch(C));
	return 0;
}