#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pii pair<int, int>
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rep3(i, l, n) for (int i = l; i < n; ++i)
#define chmax(a, b) a = (a >= b ? a : b)
#define chmin(a, b) a = (a <= b ? a : b)
#define out(a) cout << a << endl
#define outa(a, n) rep(_, n) cout << a[_] << " "; cout << endl
#define SZ(v) (int)v.size()
#define inf (int)(1e9+7)
#define abs(x) (x >= 0 ? x : -(x))

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll a, b, c;
    cin >> a >> b >> c;
    ll l = 0, r = 1e18;
    while (1) {
        ll mid = (l + r) / 2;
        if (log10(mid / a) + log10(b) > 18) { r = mid; continue; }
        ll money = mid / a * b + (mid - mid / a);
        // out(money);
        if (money < c) l = mid;
        else r = mid;
        if (l + 1 == r) break;
    }
    out(r);
}