#include<bits/stdc++.h>
#define pb emplace_back
using namespace std;
using ll = long long;
#ifdef KEV
#define DE(i, e) cerr << #i << ' ' << i << e
void debug(auto L, auto R) { while (L < R) cerr << *L << " \n"[L+1==R], ++L; }
#else
#define DE(...) 0
void debug(...) {}
#endif
const int maxn = 200010, maxm = 1000010;
const ll inf = 1ll<<55;
ll dp[maxn];
int cu[maxn], cd[maxn], T;
struct bit {
    int val[maxm];
    void reset() {
        fill(val, val+maxm, 0);
    }
    bool rev = false;
    void REV(){ rev ^= true; }
    void modify(int i, int v) {
        ++i;
        if (rev) i = maxm - i;
        for (;i < maxm;i += i&-i)
            val[i] = max(val[i], v);
    }
    int query(int i) {
        ++i;
        if (rev) i = maxm - i;
        int res = 0;
        for (;i;i ^= i&-i)
            res = max(res, val[i]);
        return res;
    }
}tree;
int n;
pair<int,int> loc[maxn];
vector<int> dep[maxn];
ll area(int a, int b) {
    return (ll)(loc[a].first-loc[b].first) * (loc[a].second-loc[b].second);
}
bool valid(int s, int t) {
    return loc[s].first < loc[t].first && loc[s].second < loc[t].second;
}
ll cal(int s, int t) {
    return valid(s, t) ? dp[s] + area(s, t) : inf;
}
void DC(const vector<int>& from, const vector<int>& to, int l, int r, int sl, int sr) {
    sl = max(sl, 0), sr = min(sr, (int)from.size()-1);
    auto getpos = [&](int x) {
        dp[x] = inf;
        int y = -1;
        for (int i = sl;i <= sr;++i) {
            ll nw = cal(from[i], x);
            if (nw < dp[x])
               dp[x] = nw, y = i;
        }
//      auto [X, Y] = loc[x];
//      DE(X, ' '), DE(Y, ' '), DE(dp[x], '\n');
        return y;
    };
    if (l > r) return;
    const int BUF = 1000;
    if (r-l+1 <= 500) {
        for (int i = l;i <= r;++i)
            getpos(to[i]);
        return;
    }

    if (l == r) {
        getpos(to[l]);
        return;
    }
    int m = l + r >> 1;
    int sm = getpos(to[m]);
    int A = sl, B = min(sr, sm+BUF), C = max(sl, sm-BUF), D = sr;
    DC(from, to, l, m-1, C, D);
    DC(from, to, m+1, r, A, B);
}

void ss(vector<int> id) {
    for (int u : id)
        dep[ cu[u] ].pb(u);
    int s = *max_element(cu, cu+n+1);
    debug(cu, cu+n+1);
    for (int i = 2;i <= s;++i) {
        DC(dep[i-1], dep[i], 0, dep[i].size()-1,
                0, dep[i-1].size()-1);
    }
    cout << dp[n] << '\n';
//  ll res = (ll)T * (ll)T;
//  for  (int u : dep[s])
//      res = min(res, dp[u]);
//  cout << res << '\n';
}
void solve() {
    tree.reset();
    for (int i = 0, x, y;i <= n;++i) {
        tie(x, y) = loc[i];
        DE(x, ' '), DE(y, '\n');
        cu[i] = tree.query(y) + 1;
        tree.modify(y, cu[i]);
    }
    tree.reset();
    tree.REV();
    for (int i = n, x, y;i >= 0;--i) {
        tie(x, y) = loc[i];
        cd[i] = tree.query(y) + 1;
        tree.modify(y, cd[i]);
    }
    int S = *max_element(cu, cu+n+1);
    vector<int> uf;
    DE(S, '\n');
    for (int i = 0;i <= n;++i) {
        if (cu[i] + cd[i] == S+1) {
        //cerr << cu[i] << ' ' << cd[i] << '\n';
            uf.pb(i);
        }
    }
    ss(uf);
}
/*
ID: ckevin31
LANG: C++14
TASK:
*/
#ifndef KEV
inline void IO(string name) {
    freopen((name + ".in").c_str(), "r", stdin);
    freopen((name + ".out").c_str(), "w", stdout);
}
#else
inline void IO(string name){}
#endif
signed main(){
    IO("mowing");
    ios_base::sync_with_stdio(0), cin.tie(0);
    cin >> n >> T;
    for (int i = 1;i <= n;++i)
        cin >> loc[i].first >> loc[i].second;
    ++n;
    loc[n] = {T, T};

    sort(loc, loc+n);
    solve();
}