#include <stdio.h>

#define HASH 1000003

typedef struct List {
	struct List *next;
	int num;
	long long v;
} list;

int main()
{
	long long N, K, M;
	scanf("%lld %lld %lld", &N, &K, &M);
	
	int h, i, n = 0, count = 0, ans = 0;
	long long A, B, tmp, l, r, m;
	list *hash[HASH] = {}, d[5000000], *p;
	for (A = 1; A <= 1000000; A++) {
		if (A + K > N / A) break;
		for (B = 2, tmp = A * (A + K); A + B * K <= N / tmp; B++) {
			tmp *= A + B * K;
			h = tmp % HASH;
			for (p = hash[h]; p != NULL; p = p->next) if (p->v == tmp) break;
			if (p != NULL) p->num++;
			else {
				d[n].v = tmp;
				d[n].num = 1;
				
				l = 1;
				r = 1000000000;
				while (l < r) {
					m = (l + r) / 2;
					if (m + K < tmp / m) l = m + 1;
					else r = m;
				}
				if (l * (l + K) == tmp) {
					d[n].num++;
					count++;
				}
				
				d[n].next = hash[h];
				hash[h] = &(d[n++]);
			}
		}
	}
	for (i = 0; i < n; i++) if (d[i].num == M) ans++;
	if (M >= 2) {
		printf("%d\n", ans);
		fflush(stdout);
		return 0;
	}
	
	l = 0;
	r = 1000000000;
	while (l < r) {
		m = (l + r + 1) / 2;
		if (m + K <= N / m) l = m;
		else r = m - 1;
	}
	printf("%d\n", ans - count + l);
	fflush(stdout);
	return 0;
}