#include <cstdio>
using namespace std;

int Min,n,k,a,b,x,i,j;
int s[500003],f[100003];
long long nr;
int main()
{
    freopen("divk.in", "r", stdin);
    freopen("divk.out", "w", stdout);
    scanf("%d", &n);
    scanf("%d%d%d", &k,&a,&b);
    for(i=1;i<=n;++i){
        scanf("%d", &x);
        s[i]=(s[i-1]+(long long)x)%k;
        if(a<=i){
            ++f[s[i-a]];
            nr+=(long long)f[s[i]];
            if(i>=b)
                --f[s[i-b]];
        }
    }
    printf("%lld", nr);
    return 0;
}