#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>
#include<utility>
#include<map>

using namespace std;

// #define int long long
#define int __int128
#define endl "\n"

constexpr long long INF = (long long)2e9;
constexpr long long MOD = 1'000'000'007; 

struct fast_io {
	fast_io(){
		std::cin.tie(nullptr);
		std::ios::sync_with_stdio(false);
	};
} fio;


int cal(int num){
    int res = 0;
    
    for(int i = 1; i <= num; i++){
        if(num % i == 0) res++;
    }
    
    return res;
}

int input(){
    long long in;
    
    cin>>in;
    
    return in;
}

int check(int P, int K){
    int l = 0, r = INF, m = 0;
    
    while(l + 1 < r){
        m = (l + r) / 2;
        
        if(m * (m + K) == P) return true;
        else if(m * (m + K) < P) l = m;
        else r = m;
    }
    
    return false;
}

signed main(){
	cout<<fixed<<setprecision(10);
	
	int N, K, M;
    int con = 0;
    map<int,int> mp;
    
    
    N = input();
    K = input();
    M = input();
	
    
    
    for(int A = 1; A * (A + K) * (A + 2 * K) <= N; A++){
        int pro = A * (A + K) * (A + 2 * K);
        for(int B = 2; pro <= N; B++){
            mp[pro]++;
            // cout<<"A = "<<(long long)A<<" B = "<<(long long)B<<" pro = "<<(long long)pro<<endl;
            pro *= A + K * (B + 1);
        }
    }
    
   if(M == 1) {
        int l = 0, r = INF, m;
        
        while(l + 1 < r){
            m = (l + r) / 2;
            
            if(m * (m + K) <= N) {
                l = m;
            } else {
                r = m;
            }
        }
        
        con = l;
        // cout<<"con = "<<(long long)con<<endl;
        
        for(pair<int,int> p : mp){
            // if((p.first) * (p.first + K) <= N) {
            if(check(p.first, K)) {
                con--;
            } else if(p.second == 1){
                con++;
            }
        }
    } else {
        
        for(pair<int,int> p : mp){
            int temp = p.second;
            
            // if((p.first) * (p.first + K) <= N) {
            if(check(p.first, K)) {
                temp++;
            }
            
            if(temp == M) con++;
        }
    }
    
    cout<<(long long)con<<endl;
    
	return 0;
}