#include<stdio.h>
#define N 500001
long c[N],n,k,a,b,i,j,t;
long long s[N]={0},l=0;
int main()
{freopen("divk.in","r",stdin);
freopen("divk.out","w",stdout);
scanf("%ld%ld%ld%ld\n",&n,&k,&a,&b);
for(i=1;i<=n;i++)
       scanf("%ld\n",&c[i]);
for(j=a;j<=b;j++)
       {for(t=1;t<=j;t++)
              s[j]+=c[t];
       if(s[j]%k==0)
              l++;}
for(t=1;t<=n;t++)
       {for(j=a;j<=b;j++)
       if(j+t<=n)
              {s[j]+=c[j+t]-c[t];
              if(s[j]%k==0)
                     l++;}}
printf("%lld\n",l);
fclose(stdin);
fclose(stdout);
return 0;}