import std.stdio, std.array, std.string, std.conv, std.algorithm;
import std.typecons, std.range, std.random, std.math, std.container;
import std.numeric, std.bigint, core.bitop, std.bitmanip;

void main() {
    immutable long MAX = 10L^18+10;

    auto s = readln.split.map!(to!long);
    auto D = s[0];
    auto Q = s[1];
    auto rbt = redBlackTree!(Tuple!(long, long))();
    long ans = 0;

    while (Q--) {
        s = readln.split.map!(to!long);
        auto a = s[0];
        auto b = s[1];
        auto lb = rbt.lowerBound(tuple(a, b));
        auto ub = rbt.upperBound(tuple(a, b));
        bool flag = 0;

        if (!lb.empty) {
            auto left = lb.back;
            if (a <= left[1] + 1) {
                rbt.removeKey(left);
                a = min(a, left[0]);
                b = max(b, left[1]);
            }
        }
        if (!ub.empty) {
            auto right = ub.front;
            if (b + 1 >= right[0]) {
                rbt.removeKey(right);
                a = min(a, right[0]);
                b = max(b, right[1]);
            }
        }

        ans = max(ans, b - a + 1);
        ans.writeln;
        rbt.insert(tuple(a, b));
    }
}