#include <stdio.h>
#define MAXN 500000
#define MAXK 100000
int fr[MAXK], sum[MAXN+1];
int main(){
    int n, a, b, k, tr, i, v;
    long long ans;
    FILE *fin, *fout;
    fin=fopen("divk.in", "r");
    fout=fopen("divk.out", "w");
    fscanf(fin, "%d%d%d%d", &n, &k, &a, &b);
    tr=0;
    for(i=1; i<=n; i++){
        fscanf(fin, "%d", &v);
        sum[i]=(sum[i-1]+v)%k;
    }
    ans=0;
    for(i=a; i<=b; i++){
        fr[sum[i-a]]++;
        ans+=fr[sum[i]];
    }
    for(i=b+1; i<=n; i++){
        fr[sum[i-b-1]]--;
        fr[sum[i-a]]++;
        ans+=fr[sum[i]];
    }
    fprintf(fout, "%lld\n", ans);
    fclose(fin);
    fclose(fout);
    return 0;
}