#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll = long long;
#define int ll
#define rng(i, a, b) for (int i = int(a); i < int(b); i++)
#define rep(i, b) rng(i, 0, b)
#define ALL(a) (a).begin(), (a).end()
template <class t, class u> void chmax(t& a, u b) {
    if (a < b) a = b;
}
template <class t, class u> void chmin(t& a, u b) {
    if (b < a) a = b;
}
template <class t> using vc = vector<t>;
template <class t> using vvc = vc<vc<t>>;
using pi = pair<int, int>;
using vi = vc<int>;
using uint = unsigned;
using ull = unsigned long long;
int popcount(signed t) { return __builtin_popcount(t); }
int popcount(ll t) { return __builtin_popcountll(t); }
bool ispow2(int i) { return i && (i & -i) == i; }
ll mask(int i) { return (ll(1) << i) - 1; }
int lcm(int a, int b) { return a / __gcd(a, b) * b; }

signed main() {
    cin.tie(0);
    ios::sync_with_stdio(0);
    cout << fixed << setprecision(20);
    int n, k, m;
    cin >> n >> k >> m;
    int u = 0, v = 0, w = 0;
    int st = m;
    for (int i = 1;; i++) {
        u += (n / st) * i;
        st *= st;
        if (st > n) break;
    }
    st = m;
    for (int i = 1;; i++) {
        v += ((n - k) / st) * i;
        st *= st;
        if (st > n - k) break;
    }
    st = m;
    for (int i = 1;; i++) {
        w += (k / st) * i;
        st *= st;
        if (st > k) break;
    }
    cout << u - v - w << endl;
}