#include <cstdio>
#include <deque>
#define pb push_back
using namespace std;
//deque <int> bst,val;
int v[1000001];
int main()
{
	int i,j,n,k,d,last=0,x;
	
	freopen("zombie.in","r",stdin);
	freopen("zombie.out","w",stdout);
	scanf("%d %d %d %d",&n,&k,&d,&x);
//	bst.pb(1);val.pb(x);
	for (i=2;i<=n;++i) 
	{scanf("%d",&v[i]);
	 //if (val.front()<x-k) last=bst.front(),val.pop_front(),bst.pop_front();
	 /*bst.pb(min(bst.back()+1,last+d));*/
	}
	printf("%d",d);
return 0;
}