#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#pragma GCC optimize("Ofast,unroll-loops")
#define ll long long
#define all(x) x.begin(), x.end()
#define ld long double
#define pii pair<int, int>
using namespace std;
using namespace __gnu_pbds;
template<class T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int INF = 1e9 + 7;
const int MAXN = 1e5 + 5;
int n, a, b;
vector<ll> ar;
int try1(ll x){
vector<int> dp(n + 1, INF);
dp[0] = 0;
for(int i = 1; i <= n; i++){
ll csum = ar[i];
for(int j = i - 1; j >= 0; j--){
if((csum | x) == x){
dp[i] = min(dp[i], dp[j] + 1);
}
csum += ar[j];
}
}
return dp[n];
}
int try2(ll x){
vector<vector<int> > dp(b + 1, vector<int>(n + 1, 0));
dp[0][0] = 1;
for(int i = 1; i <= b; i++){
for(int j = 1; j <= n; j++){
ll csum = ar[j];
for(int k = j - 1; k >= 0; k--){
if((csum | x) == x){
dp[i][j] |= dp[i - 1][k];
}
csum += ar[k];
}
}
}
int ans = 0;
for(int i = a; i <= b; i++) ans |= dp[i][n];
return ans;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> n >> a >> b;
ar.resize(n + 1);
for(int i = 1; i <= n; i++){
cin >> ar[i];
}
if(a == 1){
ll cur = (1ll << 50) - 1;
for(int i = 49; i >= 0; i--){
cur ^= (1ll << i);
if(try1(cur) > b) cur ^= (1ll << i);
}
cout << cur;
return 0;
}
else{
ll cur = (1ll << 50) - 1;
for(int i = 49; i >= 0; i--){
cur ^= (1ll << i);
if(!try2(cur)){
cur ^= (1ll << i);
if(!try2(cur)){
cout << "-1";
return 0;
}
}
}
cout << cur;
}
}
