#include <cstdio>
#include <vector>
#include <algorithm>

typedef long long ll;
typedef std::pair<ll,ll> P;

int N;
ll D, T;
ll xs[100];
bool used[100];

int main(){
    scanf("%d %lld %lld", &N, &D, &T);
    
    for(int i=0;i<N;i++){scanf("%lld", &xs[i]);}
    std::sort(xs, xs+N);

    ll res = 0ll;
    for(int i=0;i<N;i++){
        if(used[i]){continue;}
        used[i] = true;

        ll xi = xs[i];
        std::vector<P> ps;
        for(int j=i;j<N;j++){
            if((xs[j] - xi) % D == 0){
                int mid = (xs[j]-xi) / D;
                ps.push_back(std::make_pair(mid-T, mid+T));
                used[j] = true;
            }
        }

        int size = ps.size();
        for(int i=0,j=0;i<size;){
            P p = ps[i];
            while(j < size && ps[j].first <= p.second){
                p.second = ps[j].second;
                j += 1;
            }

            res += p.second - p.first + 1;
            i = j;
        }
    }

    printf("%lld\n", res);
}