#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#include "bits/stdc++.h"

using namespace std;
using ll = long long int;

#define debug(v) {printf("L%d %s > ",__LINE__,#v);cout<<(v)<<endl;}
#define debugv(v) {printf("L%d %s > ",__LINE__,#v);for(auto e:(v)){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) {printf("L%d %s > ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;}
#define debugaa(m,h,w) {printf("L%d %s >\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}}
#define ALL(v) (v).begin(),(v).end()
#define repeat(cnt,l) for(remove_const<decltype(l)>::type cnt=0;(cnt)<(l);++(cnt))
#define rrepeat(cnt,l) for(auto cnt=(l)-1;0<=(cnt);--(cnt))
#define iterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);++(cnt))
#define diterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);--(cnt))
const ll MD = 1000000007ll; const long double PI = 3.1415926535897932384626433832795L;
template<typename T1, typename T2> inline void assert_equal(T1 expected, T2 actual) { if (!(expected == actual)) { cerr << "assertion fault: expected=" << expected << " actual=" << actual << endl; abort(); } }
template<typename T1, typename T2> inline void assert_less(T1 actual, T2 threshold) { if (!(actual < threshold)) { cerr << "assertion fault: " << actual << " < (const)" << threshold << endl; abort(); } }
template<typename T1, typename T2> inline void assert_eqless(T1 actual, T2 threshold) { if (!(actual <= threshold)) { cerr << "assertion fault: " << actual << " <= (const)" << threshold << endl; abort(); } }
template<typename T1, typename T2> inline ostream& operator <<(ostream &o, const pair<T1, T2> p) { o << '(' << p.first << ':' << p.second << ')'; return o; }
template<typename Vec> inline ostream& _ostream_vecprint(ostream &o, const Vec& p) { o << '['; for (auto& e : p) o << e << ','; o << ']'; return o; }
template<typename T> inline ostream& operator<<(ostream& o, const vector<T>& v) { return _ostream_vecprint(o, v); }
template<typename T, size_t S> inline ostream& operator<<(ostream& o, const array<T, S>& v) { return _ostream_vecprint(o, v); }
template<typename T> inline T& maxset(T& to, const T& val) { return to = max(to, val); }
template<typename T> inline T& minset(T& to, const T& val) { return to = min(to, val); }
void bye(string s, int code = 0) { cout << s << endl; exit(code); }
mt19937_64 randdev(8901016);
template<typename T> inline T rand(T l, T h) { return uniform_int_distribution<T>(l, h)(randdev); }
template<> inline double rand<double>(double l, double h) { return uniform_real_distribution<double>(l, h)(randdev); }
template<> inline float rand<float>(float l, float h) { return uniform_real_distribution<float>(l, h)(randdev); }

#if defined(_WIN32) || defined(_WIN64)
#define getchar_unlocked _getchar_nolock
#define putchar_unlocked _putchar_nolock
#elif defined(__GNUC__)
#else
#define getchar_unlocked getchar
#define putchar_unlocked putchar
#endif
namespace {
#define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E)
    class MaiScanner {
    public:
        template<typename T> void input_integer(T& var) {
            var = 0; T sign = 1;
            int cc = getchar_unlocked();
            for (; cc<'0' || '9'<cc; cc = getchar_unlocked())
                if (cc == '-') sign = -1;
            for (; '0' <= cc && cc <= '9'; cc = getchar_unlocked())
                var = (var << 3) + (var << 1) + cc - '0';
            var = var * sign;
        }
        inline int c() { return getchar_unlocked(); }
        inline MaiScanner& operator>>(int& var) { input_integer<int>(var); return *this; }
        inline MaiScanner& operator>>(long long& var) { input_integer<long long>(var); return *this; }
        inline MaiScanner& operator>>(string& var) {
            int cc = getchar_unlocked();
            for (; !isvisiblechar(cc); cc = getchar_unlocked());
            for (; isvisiblechar(cc); cc = getchar_unlocked())
                var.push_back(cc);
            return *this;
        }
        template<typename IT> void in(IT begin, IT end) { for (auto it = begin; it != end; ++it) *this >> *it; }
    };
    class MaiPrinter {
    public:
        template<typename T>
        void output_integer(T var) {
            if (var == 0) { putchar_unlocked('0'); return; }
            if (var < 0)
                putchar_unlocked('-'),
                var = -var;
            char stack[32]; int stack_p = 0;
            while (var)
                stack[stack_p++] = '0' + (var % 10),
                var /= 10;
            while (stack_p)
                putchar_unlocked(stack[--stack_p]);
        }
        inline MaiPrinter& operator<<(char c) { putchar_unlocked(c); return *this; }
        inline MaiPrinter& operator<<(int var) { output_integer<int>(var); return *this; }
        inline MaiPrinter& operator<<(long long var) { output_integer<long long>(var); return *this; }
        inline MaiPrinter& operator<<(char* str_p) { while (*str_p) putchar_unlocked(*(str_p++)); return *this; }
        inline MaiPrinter& operator<<(const string& str) {
            const char* p = str.c_str();
            const char* l = p + str.size();
            while (p < l) putchar_unlocked(*p++);
            return *this;
        }
        template<typename IT> void join(IT begin, IT end, char sep = '\n') { for (auto it = begin; it != end; ++it) *this << *it << sep; }
    };
}
MaiScanner scanner;
MaiPrinter printer;



struct SegmentTreeS {

    struct Node {
        ll val_;
        bool lazy_ = false;
        unique_ptr<Node> bottom[2];

        Node(ll v, bool lz = false) : val_(v), lazy_(lz) {

        }

        inline void setup_bottom() {
            if (!bottom[0]) bottom[0].reset(new Node(0));
            if (!bottom[1]) bottom[1].reset(new Node(0));
        }

        inline void apply_lazy() {
            bottom[0]->lazy_ = true;
            bottom[0]->val_ = val_ / 2;
            bottom[1]->lazy_ = true;
            bottom[1]->val_ = val_ / 2;
        }

        void set_range(ll begin, ll end, ll left, ll right) {
            if (end <= left || right <= begin) return; // out of range
            if (begin <= left && right <= end) {
                val_ = right - left;
                lazy_ = true;
                return;
            }
            setup_bottom();
            if (lazy_) apply_lazy();

            ll center = (right + left) / 2;
            bottom[0]->set_range(begin, end, left, center);
            bottom[1]->set_range(begin, end, center, right);
            val_ = (bottom[0]->val_ + bottom[1]->val_);
        }

        void reset_range(ll begin, ll end, ll left, ll right) {
            if (end <= left || right <= begin) return; // out of range
            if (begin <= left && right <= end) {
                val_ = right - left;
                lazy_ = true;
                return;
            }
            setup_bottom();
            if (lazy_) apply_lazy();

            ll center = (right + left) / 2;
            bottom[0]->reset_range(begin, end, left, center);
            bottom[1]->set_range(begin, end, center, right);
            val_ = (bottom[0]->val_ + bottom[1]->val_);
        }

        ll count_range(ll begin, ll end, ll left, ll right) {
            if (end <= left || right <= begin) return 0;
            if (begin == left && right == end) return val_;
            if (val_ == 0) return val_;
            if (val_ == right - left) return min(right, end) - max(left, begin);
            ll center = (right + left) / 2;
            return
                bottom[0]->count_range(begin, end, left, center)
                + bottom[1]->count_range(begin, end, center, right);
        }
    };

    ll width;
    Node root;

    SegmentTreeS(ll w) :root(0, false) {
        width = 8;
        while (width < w) width <<= 1;
    }

    inline void set_range(ll begin, ll end) {
        root.set_range(begin, end, 0, width);
    }
    inline void reset_range(ll begin, ll end) {
        root.reset_range(begin, end, 0, width);
    }
    inline ll count_range(ll begin, ll end) {
        return root.count_range(begin, end, 0, width);
    }
};




ll D, Q;


// ll dfs_left(const SegmentTreeS::Node& node, ll index, ll left, ll right) {
//     cout << '<' << make_pair(left, right) << endl;
//     if (index < left) return index;
//     if (node.val_ == 0) return index;
//     if (node.val_ == right - left) return left;
//     ll center = (right + left) / 2;
//     ll ans = dfs_left(*node.bottom[1], index, center, right);
//     if (index <= ans) minset(ans, dfs_left(*node.bottom[0], index, left, center));
//     return ans;
// }
// ll dfs_right(const SegmentTreeS::Node& node, ll index, ll left, ll right) {
//     cout << '>' << make_pair(left, right) << endl;
//     if (right <= index) return index;
//     if (node.val_ == 0) return index;
//     if (node.val_ == right - left) return right - 1;
//     ll center = (right + left) / 2;
//     ll ans = dfs_right(*node.bottom[0], index, left, center);
//     if (ans <= index) maxset(ans, dfs_right(*node.bottom[1], index, center, right));
//     return ans;
// }


typedef ll bsearch_t;
bsearch_t bin_search(bsearch_t false_val, bsearch_t true_val, function<bool(bsearch_t)> func) {
    while (abs(true_val - false_val) > 1) {
        bsearch_t c = (true_val + false_val) / 2;
        (func(c) ? true_val : false_val) = c;
    }
    return true_val;
}

int main() {

    scanner >> D >> Q;
    SegmentTreeS seg(D + 1);

    ll ans = 0;

    repeat(lop, Q) {

        ll a, b;
        scanner >> a >> b;
        ++b;

        maxset(ans, b - a);

        seg.set_range(a, b);

        // ll left = dfs_left(seg.root, a, 0, seg.width);
        // ll right = dfs_right(seg.root, b - 1, 0, seg.width);
        // 
        // cout << make_pair(right, left) << endl;
        // 
        // maxset(ans, right - left + 1);
 
        ll left = bin_search(-1, a, [&](ll x) {return seg.count_range(x, a + 1) == a + 1 - x; });
        ll right = bin_search(D+1, b, [&](ll x) {return seg.count_range(b-1, x) == x - b + 1; });

        maxset(ans, right - left);

        printer << ans << '\n';
    }

    return 0;
}