#include<fstream.h>
#define N 500001
long c[N],n,k,a,b,i,j,t;
long long s[N]={0},l=0;
int main()
{ifstream f1("divk.in");
ofstream f2("divk.out");
f1>>n>>k>>a>>b;
for(i=1;i<=n;i++)
       {f1>>c[i];
       if(i<a)
              s[a]+=c[i];
       else
              if(i==a)
                     {s[a]+=c[i];
                     if(s[a]%k==0)
                             l++;}}
for(j=a+1;j<=b;j++)
       {s[j]=s[j-1]+c[j];
       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++;}}
f2<<l;
f1.close();
f2.close();
return 0;}