#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
#define F first
#define S second
#define PB push_back
void FASTIO() {ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); }
const int MXN = 1e6+5;
int n, a, b;
int T[MXN];
int dp[MXN];
multiset<int> MS1;
multiset<int> MS2;
vector<int> event[2*MXN];
bool moved[2*MXN];
int main() {
FASTIO();
cin >> n >> a >> b;
for(int i = 1; i <= n; i++) {
cin >> T[i];
}
sort(T+1, T+n+1);
fill(dp, dp+n+1, MXN);
dp[0] = 0;
int j = 0;
for(int i = 1; i <= n; i++) {
for(; j <= T[i]; j++) {
//cerr << "j = " << j << "\n";
while(!event[j].empty()) {
int x = event[j].back();
if(moved[x]) {
event[j].pop_back();
continue;
}
moved[x] = true;
MS1.erase(MS1.find(dp[x]));
MS2.insert(T[x+1]);
event[j].pop_back();
}
} j--;
int l = i-b, r = i-a;
if(r < 0) continue;
if(l-1 >= 0) {
if(!moved[l-1]) MS1.erase(MS1.find(dp[l-1]));
else MS2.erase(MS2.find(T[l]));
moved[l-1] = true;
}
if(T[r+1]+dp[r] > T[i]) {
MS1.insert(dp[r]);
event[T[r+1]+dp[r]].PB(r);
}
else {
moved[r] = true;
MS2.insert(T[r+1]);
}
if(!MS1.empty()) dp[i] = min(dp[i], *MS1.begin());
if(!MS2.empty()) dp[i] = min(dp[i], T[i]-(*MS2.rbegin()));
}
cout << dp[n] << "\n";
return 0;
}
/*
*/
