#include <bits/stdc++.h>
#define MAX 131072
#define ll long long

using namespace std;
const int NMAX = 500004;
const int KMAX = 100004;

FILE *IN, *OUT;

ll N, K, A, B, sol;
ll S[NMAX], R[KMAX];

int pos, sign, out;
char f[MAX], Out[MAX], str[10];

inline void Write_Ch(char ch){
    Out[out++] = ch;
    if(out == MAX)
        fwrite(Out, MAX, 1, OUT), out = 0;
}

inline void Write_Int(long long nr){
    int x = 0;
    if(nr < 0) Write_Ch('-'), nr = -nr;
    do{
        str[x++] = nr % 10 + '0';
        nr /= 10;
    } while(nr);
    while(x > 0)
        Write_Ch(str[--x]);
}

inline void Read(long long &nr){
    sign = 0;
    nr = 0;
    while(f[pos] < '0' || f[pos] > '9'){
        if(f[pos] == '-') sign = 1;
        pos++;
        if(pos == MAX)
            fread(f, MAX, 1, IN), pos = 0;
    }
    while(f[pos] >= '0' && f[pos] <= '9'){
        nr = 10 * nr + f[pos++] - '0';
        if(pos == MAX)
            fread(f, MAX, 1, IN), pos = 0;
    }
    if(sign) nr =- nr;
}

int main(){

    IN = fopen("divk.in", "r");
    OUT = fopen("divk.out", "w");

    Read(N); Read(K); Read(A); Read(B);
    long long x;
    for(int i = 1; i <= N; i++){
        Read(x);
        S[i] = S[i - 1] + x;
        if(i - B - 1 >= 0)
            R[S[i - B - 1] % K]--;
        if(i - A >= 0)
            R[S[i - A] % K]++;
        sol += R[S[i] % K];
    }

    Write_Int(sol);
    if(out > 0) fwrite(Out, 1, out, OUT);

    return 0;
}