#include <fstream>
#include <iostream>

using namespace std;

const int nmax = 1000010;
int A[nmax], B[nmax];

int bin(int v)
{
}

const int DIM = 1 << 13;
int poz = DIM - 1;
char buf[DIM];
int X;

inline int nr()
{
    X = 0;
    while(!isdigit(buf[poz]))
        if(++poz == DIM)
            fread(buf, sizeof(char), DIM, stdin), poz = 0;

    while(isdigit(buf[poz]))
    {
        X = X * 10 + buf[poz] - '0';

        if(++poz == DIM)
            fread(buf, sizeof(char), DIM, stdin), poz = 0;
    }
    return X;
}

int main()
{
    freopen ("zombie.in", "r", stdin);
    freopen ("zombie.out", "w", stdout);

    int D, N, K, i, ind, j;
    D = nr();N = nr();K = nr();
    for(i = 1; i <= N; i++)
        A[i] = nr();

    B[1] = 1;
    for(i = 2; i <= N; i++)
    {
        B[i] = B[i - 1] + 1;

        ind = 0;

        for(j = 1; A[j] <= A[i] - D; j <<= 1);
        for(j >>= 1; j > 0; j >>= 1)
            if(A[j + ind] <= A[i] - D)
                ind += j;

        if(B[i] > B[ind] + K)
            B[i] = B[ind] + K;
    }

    printf("%d\n", B[N]);
    return 0;
}