#include<bits/stdc++.h>
#define LL long long
#define LD long double
#define ull unsigned long long
#define fi first
#define se second
#define mk make_pair
#define PLL pair<LL, LL>
#define PLI pair<LL, int>
#define PII pair<int, int>
#define SZ(x) ((int)x.size())
#define ALL(x) (x).begin(), (x).end()
#define fio ios::sync_with_stdio(false); cin.tie(0);using namespace std;const int N = 5e4 + 10;
const int inf = 0x3f3f3f3f;
const LL INF = 0x3f3f3f3f3f3f3f3f;
const int mod = 1e9 + 7;
const double eps = 1e-8;
const double PI = acos(-1);template<class T, class S> inline void add(T& a, S b) {a += b; if(a >= mod) a -= mod;}
template<class T, class S> inline void sub(T& a, S b) {a -= b; if(a < 0) a += mod;}
template<class T, class S> inline bool chkmax(T& a, S b) {return a < b ? a = b, true : false;}
template<class T, class S> inline bool chkmin(T& a, S b) {return a > b ? a = b, true : false;}const int LOG = 30;int n, a[N];
LL m;
LL sum, num;struct Trie {int ch[N * LOG][2], cnt[N * LOG];int f[N * LOG][30];int tot;void init() {tot = 1;}void ins(int x) {int u = 1;for(int i = LOG - 1; i >= 0; i--) {cnt[u]++;for(int j = LOG - 1; j >= 0; j--) f[u][j] += (x >> j & 1);if(!ch[u][x >> i & 1]) ch[u][x >> i & 1] = ++tot;u = ch[u][x >> i & 1];}for(int j = LOG - 1; j >= 0; j--) f[u][j] += (x >> j & 1);cnt[u]++;}PLL query(int x, int k, int op) {int u = 1;int now = 0;LL ans = 0;LL sum = 0;for(int i = LOG - 1; i >= 0 && u; i--) {if(x >> i & 1) {if(now + (1 << i) >= k) {ans += cnt[ch[u][0]];if(op) {for(int j = LOG - 1; j >= 0; j--) {if(x >> j & 1) sum += 1LL * (1 << j) * (cnt[ch[u][0]] - f[ch[u][0]][j]);else sum += 1LL * (1 << j) * f[ch[u][0]][j];}}u = ch[u][1];} else {u = ch[u][0];now += 1 << i;}} else {if(now + (1 << i) >= k) {ans += cnt[ch[u][1]];if(op) {for(int j = LOG - 1; j >= 0; j--) {if(x >> j & 1) sum += 1LL * (1 << j) * (cnt[ch[u][1]] - f[ch[u][1]][j]);else sum += 1LL * (1 << j) * f[ch[u][1]][j];}}u = ch[u][0];} else {u = ch[u][1];now += 1 << i;}}}if(now == k) ans += cnt[u], sum += 1LL * cnt[u] * now;return mk(ans, sum);}
} trie;bool check(int x, int op) {sum = 0; num = 0;for(int i = 1; i <= n; i++) {PLL tmp = trie.query(a[i], x, op);num += tmp.fi; sum += tmp.se;}num /= 2; sum /= 2;return num >= m;
}int main() {trie.init();scanf("%d%lld", &n, &m);for(int i = 1; i <= n; i++) scanf("%d", &a[i]);for(int i = 1; i <= n; i++) trie.ins(a[i]);int low = 0, high = (1 << 30) - 1, up = 0;while(low <= high) {int mid = low + high >> 1;if(check(mid, 0)) up = mid, low = mid + 1;else high = mid - 1;}check(up, 1);sum -= 1LL * (num - m) * up;printf("%lld", sum % mod);return 0;
}/*
*/