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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        long n = sc.nextLong();
        long k = sc.nextLong();
        long m = sc.nextLong();
        HashMap<Long, Integer> counts = new HashMap<>();
        for (long i = 2; i <= Math.sqrt(m); i++) {
            while (m % i == 0) {
                counts.put(i, counts.getOrDefault(i, 0) + 1);
                m /= i;
            }
        }
        if (m > 1) {
            counts.put(m, counts.getOrDefault(m, 0) + 1);
        }
        long ans = Long.MAX_VALUE;
        for (long x : counts.keySet()) {
            int c = counts.get(x);
            long all = getCount(n, x);
            long minus1 = getCount(k, x);
            long minus2 = getCount(n - k, x);
            ans = Math.min(ans, (all - minus1 - minus2) / c);
        }
        System.out.println(ans);
    }
    
    static long getCount(long target, long x) {
        long count = 0;
        long y = 1;
        while (target / y >= x) {
            y *= x;
            count += target / y;
        }
        return count;
    }
}

class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        if (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}