Problem: There is a grid of squares with H+1 horizontal rows and W vertical columns.

You will start at one of the squares in the top row and repeat moving one square right or down. However, for each integer i from 1 through H, you cannot move down from the A_i-th, (A_i + 1)-th, \ldots, B_i-th squares from the left in the i-th row from the top.

For each integer k from 1 through H, find the minimum number of moves needed to reach one of the squares in the (k+1)-th row from the top. (The starting square can be chosen individually for each case.) If, starting from any square in the top row, none of the squares in the (k+1)-th row can be reached, print `-1` instead.

Constraints

* 1 \leq H,W \leq 2\times 10^5
* 1 \leq A_i \leq B_i \leq W

Input

Input is given from Standard Input in the following format:


H W
A_1 B_1
A_2 B_2
:
A_H B_H


Output

Print H lines. The i-th line should contain the answer for the case k=i.

Example

Input

4 4
2 4
1 1
2 3
2 4


Output

1
3
6
-1

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {
    int h, w;
    cin >> h >> w;

    // map of (start index, current index)
    map<int, int> s;
    // times took right step
    multiset<int> vals;

    for (int i = 0; i < w; ++i) {
        s[i] = i;
        vals.insert(0);
    }

    for (int i = 0; i < h; ++i) {
        int l, r;
        cin >> l >> r;
        l--;
        auto itr = s.lower_bound(l);
        int till = -1;
        while(itr != s.end() && itr->first <= r) {
            till = max(till, itr->second);
            int x = itr->first - itr->second;
            vals.erase(vals.find(x));
            s.erase(itr++);
        }
        if(till != -1 && r < w) {
            vals.insert(r - till);
            s[r] = till;
        }

        int ans = -1;
        if(vals.size()) {
            ans = *vals.begin() + (i+1);
        }
        cout << ans << endl;
    }
}