#include #include #include #include #include #include #include #include #include #include #include #include #include #include #define int long long int #define rep(i, n) for(int i = 0; i < (n); ++i) using namespace std; typedef pair P; const int INF = 1e18; const int MOD = 1e9+7; signed main(){ int d, q; cin >> d >> q; set

range; range.emplace(-INF-10, -INF-10); range.emplace(INF+10, INF+10); int ans = 0; rep(i, q){ int a, b; cin >> a >> b; P r = make_pair(a, b); auto x_ = range.lower_bound(r); x_--; P x = *x_; if(x.second + 1 >= r.first){ r.first = x.first; r.second = max(r.second, x.second); range.erase(x); } auto y_ = range.upper_bound(r); P y = *y_; while(y.first <= r.second + 1){ r.second = max(r.second, y.second); y_ = range.erase(y_); y = *y_; } range.insert(r); int len = r.second - r.first + 1; if(ans < len){ ans = len; } cout << ans << endl; } return 0; }