import java.util.*; 
import java.io.*; 
import java.math.*;

class Main{
    void solve() {
        long A = in.nextLong() , B = in.nextLong(), K = in.nextLong();
        long l = 0 , r = (long)8e18;
        long lcm = lcm(A , B);
        while(r - l > 1) {
            long mid = (r + l) / 2 ;
            if(getCount(A, B ,lcm , mid) < K) {
                l = mid ;
            }
            else{
                r = mid ;
            }
        }
        out.print(r);
    }
    long getCount(long A , long B , long C , long D) {
        return D / A + D / B - D / C ;
    }
    long gcd(long a, long b) { return b == 0 ? a: gcd(b, a % b); }
    long lcm(long a, long b) { return a / gcd(a, b) * b; }
    public static void main(String[] args) {
        new Main().solve();
        out.flush();
    }
    static PrintWriter out = new PrintWriter(System.out);
    static In in  = new In();
    static final long MOD7 = 1000000007;
    static final long MOD9 = 998244353 ;
    static final int  inf = (1 << 30);
    static final long lnf = (1L << 60);
    final String yes = "Yes";
    final String no  = "No" ;
    List<Pair<Integer,Integer>> dir4 = new ArrayList<>() {{
        add(new Pair<>(0,-1));
        add(new Pair<>(1,0));
        add(new Pair<>(0,1));
        add(new Pair<>(-1,0));
    }};
    List<Pair<Integer,Integer>> dir8 = new ArrayList<>() {{
        add(new Pair<>(-1,0));
        add(new Pair<>(-1,1));
        add(new Pair<>(0,1));
        add(new Pair<>(1,1));
        add(new Pair<>(1,0));
        add(new Pair<>(1,-1));
        add(new Pair<>(0,-1));
        add(new Pair<>(-1,-1));
    }};
}
class Permutation {

    private int [] perm ;
    private int [] tmp  ;
    private int [] used ;
    private int size = 0;
    private int len  = 1;
    private int cur = 0;
    private ArrayList<int []> perm_list ;

    public Permutation(int n) {
        this.perm_list = new ArrayList<int []>();
        this.perm = new int[n];
        this.tmp  = new int[n];
        this.used = new int[n];
        len  = 1;
        size = n ;
        for(int i = 0 ; i < n ; i ++ ) perm[i] = i ;
        for(int i = n ; i > 0 ; i -- ) len *= i;
        for(int i = 0 ; i < len ; i ++ ) perm_list.add(new int[n]);
    }   
    public ArrayList<int []> getList() {
        next_permutation(0);
        return perm_list;
    }
    private void next_permutation(int idx){
        if(idx == size) {
            for(int i = 0 ; i < size ; i ++ ) {
                perm_list.get(cur)[i] = tmp[i];
            }
            cur++;
            return;
        }
        for(int i=0;i<size;i++) {
            if(used[i] == 1) continue;
            used[i] = 1;
            tmp[idx] = perm[i];
            next_permutation(idx+1);
            used[i] = 0;
        }
    }
}
class Pair<T extends Comparable<T>, U extends Comparable<U>> implements Comparable<Pair<T, U>> {
    private final T first;
    private final U second;

    Pair(T first, U second) {
        this.first = first;
        this.second = second;
    }

    T getFirst() {
        return first;
    }

    U getSecond() {
        return second;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Pair<?, ?> pair = (Pair<?, ?>) o;
        return Objects.equals(first, pair.first) &&
                Objects.equals(second, pair.second);
    }

    @Override
    public int hashCode() {
        return Objects.hash(first, second);
    }

    @Override
    public int compareTo(Pair<T, U> other) {
        T small_First  = this.first  , large_First  = other.first;
        U small_Second = this.second , large_Second = other.second;
        int First_Result  = small_First.compareTo(large_First);
        int Second_Result = small_Second.compareTo(large_Second);
        return First_Result == 0 ? Second_Result : First_Result ;
    }

    @Override
    public String toString() {
        return this.first+" "+this.second;
    }
}
class Triple<T extends Comparable<T>, U extends Comparable<U>, V extends Comparable<V>> implements Comparable<Triple<T, U, V>> {
    private final T first;
    private final U second;
    private final V third;

    Triple(T first, U second, V third) {
        this.first = first;
        this.second = second;
        this.third = third;
    }

    T getFirst() {
        return first;
    }

    U getSecond() {
        return second;
    }

    V getThird() {
        return third;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Triple<?, ?, ?> triple = (Triple<?, ?, ?>) o;
        return Objects.equals(first, triple.first) &&
                Objects.equals(second, triple.second) &&
                Objects.equals(third, triple.third);
    }

    @Override
    public int hashCode() {
        return Objects.hash(first, second, third);
    }

    @Override
    public int compareTo(Triple<T, U, V> other) {
        T small_First  = this.first  , large_First  = other.first;
        U small_Second = this.second , large_Second = other.second;
        V small_Third  = this.third  , large_Third  = other.third;
        int First_Result  = small_First.compareTo(large_First);
        int Second_Result = small_Second.compareTo(large_Second);
        int Third_Result  = small_Third.compareTo(large_Third);
        return First_Result == 0 ? (Second_Result == 0 ? Third_Result : Second_Result ) : First_Result;
    }
}
class In{
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { 
        if (hasNextByte()) return buffer[ptr++]; else return -1;
    }
    private static boolean isPrintableChar(int c) { 
        return 33 <= c && c <= 126;
    }
    public boolean hasNext() { 
        while(hasNextByte() && !isPrintableChar(buffer[ptr])) {
            ptr++; 
        }
        return hasNextByte();
    }
    String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    double nextDouble() { 
        return Double.parseDouble(next());
    }
    char nextChar() {
        return next().charAt(0);
    }
    int [] IntArray(int n) {
        final int [] Array = new int [n];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = nextInt();
        }
        return Array;
    }
    int [][] IntArray(int n , int m) {
        final int [][] Array = new int [n][m];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = IntArray(m);
        }
        return Array;
    }   
    long [] LongArray(int n) {
        final long [] Array = new long [n];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = nextLong();
        }
        return Array;
    }
    long [][] LongArray(int n , int m) {
        final long [][] Array = new long [n][m];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = LongArray(m);
        }
        return Array;
    }
    String [] StringArray(int n) {
        final String [] Array = new String [n];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = next();
        }
        return Array;
    }
    char [] CharArray(int n) {
        final char [] Array = new char[n];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = next().charAt(0);
        }
        return Array;
    }
    char [][] CharArray(int n , int m) {
        final char [][] Array = new char [n][m];
        for(int i = 0 ; i < n ; i ++ ) {
            Array[i] = next().toCharArray();
        }
        return Array;
    }
    char [][] CharArray2(int n , int m) {
        final char [][] Array = new char [n][m];
        for(int i = 0 ; i < n ; i ++ ) {
            for(int j = 0 ; j < n ; j ++ ) {
                Array[i][j] = next().charAt(0);
            }
        }
        return Array;
    }
}