#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vint;
typedef pair<int,int> pint;
typedef vector<pint> vpint;
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for(int i=n-1;i>=(0);i--)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
#define all(v) (v).begin(),(v).end()
#define eall(v) unique(all(v), v.end())
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define chmax(a, b) a = (((a)<(b)) ? (b) : (a))
#define chmin(a, b) a = (((a)>(b)) ? (b) : (a))
const int MOD = 1e9 + 7;
const int INF = 1e9;
const ll INFF = 1e18;



int main() {
	ll a, b, c; cin >> a >> b >> c;
	ll l = 0, r = INFF + 2;
	while(r - l > 1) {
		// printf("%lld %lld\n", l, r);
		ll m = (l + r) / 2;
		ll num = m / a;
		ll sum = num * b + (m - num);
		if(sum < c) l = m + 1;
		else r = m;
	}	
	printf("%lld\n", l);
	return 0;
}