#include <algorithm>
#include <bitset>
#include <cmath>
#include <complex>
#include <cstdio>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <sys/types.h>
#include <unistd.h>
#include <vector>

#pragma region macros
#define _overload(_1, _2, _3, name, ...) name
#define _rep(i, n) _range(i, 0, n)
#define _range(i, a, b) for (int i = int(a); i < int(b); ++i)
#define rep(...) _overload(__VA_ARGS__, _range, _rep, )(__VA_ARGS__)
#define _rrep(i, n) _rrange(i, n, 0)
#define _rrange(i, a, b) for (int i = int(a) - 1; i >= int(b); --i)
#define rrep(...) _overload(__VA_ARGS__, _rrange, _rrep, )(__VA_ARGS__)
#pragma endregion macros

using namespace std;

template <class T> bool chmax(T &a, const T &b) {
    return (a < b) ? (a = b, 1) : 0;
}
template <class T> bool chmin(T &a, const T &b) {
    return (b < a) ? (a = b, 1) : 0;
}

using ll    = long long;
using R     = long double;
const R EPS = 1e-9L;  // [-1000,1000]->EPS=1e-8 [-10000,10000]->EPS=1e-7
inline int sgn(const R &r) {
    return (r > EPS) - (r < -EPS);
}
inline R sq(R x) {
    return sqrt(max(x, 0.0L));
}

const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};

const pid_t pid = getpid();
// Problem Specific Parameter:


int main(void) {
    ll a, b, k;
    cin >> a >> b >> k;

    const ll c = lcm(a, b);

    ll low = 0LL, high = 1LL << 60;

    while (high - low > 1) {
        const ll mid = (low + high) / 2LL;
        const ll num = mid / a + mid / b - mid / c;

        if (num < k) {
            low = mid;
        } else {
            high = mid;
        }
    }

    cout << high << endl;

    return 0;
}