#include <bits/stdc++.h>

using namespace std;

namespace {

    typedef double real;
    typedef long long ll;

    template<class T> ostream& operator<<(ostream& os, const vector<T>& vs) {
        if (vs.empty()) return os << "[]";
        auto i = vs.begin();
        os << "[" << *i;
        for (++i; i != vs.end(); ++i) os << " " << *i;
        return os << "]";
    }
    template<class T> istream& operator>>(istream& is, vector<T>& vs) {
        for (auto it = vs.begin(); it != vs.end(); it++) is >> *it;
        return is;
    }

    ll A, B, T;
    void input() {
        cin >> A >> B >> T;
    }

    ll next(ll r) {
        ll d = B % A;
        ll ans = r - d;
        if (ans < 0) ans += A;
        return ans;
    }

    const ll INF = LLONG_MAX;

    ll calc(ll A, ll B) {
        ll r = T % A;
        if (r == 0) {
            return T;
        }
        ll ans = INF;
        ll b_count = 0;
        set<ll> found;
        found.insert(r);
        for (int i = 0; i < A; i++) {
            b_count++;
            if (B * b_count > T) {
                ans = min(ans, B * b_count);
                break;
            }
            r = next(r);
            if (r == 0) {
                return T;
            }
            found.insert(r);
        }
        auto it = found.end();
        it--;
        return min(ans, T + A - *it);
    }

    void solve() {
        cout << calc(A, B) << endl;
    }
}

int main() {
    input(); solve();
    return 0;
}