import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


long calc(long p, long n) {
  long ret;
  for (; (n /= p) > 0; ) {
    ret += n;
  }
  return ret;
}

void main() {
  try {
    for (; ; ) {
      const N = readLong;
      const K = readLong;
      const M = readLong;
      
      long ans = long.max;
      void check(long p, long e) {
        long f;
        f += calc(p, N);
        f -= calc(p, K);
        f -= calc(p, N - K);
        chmin(ans, f / e);
      }
      
      {
        long m = M;
        for (long p = 2; p * p <= m; ++p) if (m % p == 0) {
          long e;
          do {
            ++e;
            m /= p;
          } while (m % p == 0);
          check(p, e);
        }
        if (m > 1) {
          check(m, 1);
        }
      }
      
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}