// yukicoder: 33 アメーバがたくさん
// 2019.5.27 bal4u

#include <stdio.h>
#include <stdlib.h>

#if 1
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif
int in() {  // 整数の入力（負数対応）
	int n = 0, c = gc();
	if (c == '-') {	c = gc();
		do n = 10*n + (c & 0xf), c = gc(); while (c >= '0');
		return -n;
	}
	do n = 10*n + (c & 0xf), c = gc(); while (c >= '0');
	return n;
}

int x[102];
long long l[102], r[102];
int f[102];

int cmp(const void *a, const void *b) { return *(int *)a - *(int *)b; }

int main()
{
	int i, j, N, D, T;
	long long ans;
	
	N = in(), D = in(), T = in();
	for (i = 0; i < N; i++) x[i] = in();
	qsort(x, N, sizeof(int), cmp);
	for (i = 0; i < N; i++) {
		l[i] = x[i]-(long long)T*D, r[i] = x[i]+(long long)T*D;
		for (j = 0; j < i; j++) if (!f[j]) {
			if ((x[i]-x[j]) % D == 0 && r[j] >= l[i])
				l[i] = l[j], f[j] = 1;
		}
	}
	ans = 0;
	for (i = 0; i < N; i++)
		if (!f[i]) ans += (r[i]-l[i])/D+1;
	printf("%lld\n", ans);
	return 0;
}