#include<stdio.h>
#include<vector>
#include <algorithm>
using namespace std;

int main(){
    long long int m,k,h;
    long long int sum=0;
    scanf("%lld %lld %lld",&m,&k,&h);
    int *steps=new int[m];
    for(int i=0;i<m;i++){
        scanf("%d",&steps[i]);
    }
    vector<int> insightSteps;
    for(long long int i=0;i<k&&i<m;i++){
        insightSteps.push_back(steps[i]);
    }
    sort(insightSteps.begin(),insightSteps.end());
    for(long long int i=0;i<m;i++){
        insightSteps.erase(find(insightSteps.begin(),insightSteps.end(),steps[i]));
        auto ip=insightSteps.begin();
        if(i+k<m){
            ip=lower_bound(insightSteps.begin(),insightSteps.end(),steps[i+k]);
            insightSteps.insert(ip,steps[i+k]);
        }
        long long int lowest=steps[i]-h;
        lowest=lowest<0?0:lowest;
        long long int highest=steps[i]+h;
        highest=highest>2147483647?2147483647:highest;
        auto lb=lower_bound(insightSteps.begin(),insightSteps.end(),lowest);
        auto ub=upper_bound(insightSteps.begin(),insightSteps.end(),highest);
        sum+=ub-lb;
    }
    printf("%lld\n",sum);
    delete[] steps;
    return 0;
}