#include using namespace std; using ll = long long; using pll = pair; #define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i) #define rep(i, n) drep(i, 0, n - 1) #define all(a) (a).begin(), (a).end() #define pb push_back #define fi first #define se second mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count()); const ll MOD1000000007 = 1000000007; const ll MOD998244353 = 998244353; const ll MOD[3] = {999727999, 1070777777, 1000000007}; const ll LINF = 1LL << 60; const int IINF = 1 << 30 - 1; template struct Edge{ int to; T w; Edge(int to_, T w_=1){ to = to_; w=w_; } }; template using Tree = vector>>; template using Graph = vector>>; /* 容量&重み付きエッジ for Dinic */ template struct REdge{ int to; T cap; T cost; int rev; REdge(int to_, T cap_, T cost_=1){ to = to_; cap = cap_; cost = cost_; } REdge(int to_, T cap_, T cost_, int rev_){ to = to_; cap = cap_; cost = cost_; rev = rev_; } }; /* 残余グラフ for Dinic */ template using RGraph = vector>>; template class modint{ long long x; public: modint(long long x=0) : x((x%mod+mod)%mod) {} modint operator-() const { return modint(-x); } bool operator==(const modint& a){ if(x == a) return true; else return false; } bool operator==(long long a){ if(x == a) return true; else return false; } bool operator!=(const modint& a){ if(x != a) return true; else return false; } bool operator!=(long long a){ if(x != a) return true; else return false; } modint& operator+=(const modint& a) { if ((x += a.x) >= mod) x -= mod; return *this; } modint& operator-=(const modint& a) { if ((x += mod-a.x) >= mod) x -= mod; return *this; } modint& operator*=(const modint& a) { (x *= a.x) %= mod; return *this; } modint operator+(const modint& a) const { modint res(*this); return res+=a; } modint operator-(const modint& a) const { modint res(*this); return res-=a; } modint operator*(const modint& a) const { modint res(*this); return res*=a; } modint pow(long long t) const { if (!t) return 1; modint a = pow(t>>1); a *= a; if (t&1) a *= *this; return a; } // for prime mod modint inv() const { return pow(mod-2); } modint& operator/=(const modint& a) { return (*this) *= a.inv(); } modint operator/(const modint& a) const { modint res(*this); return res/=a; } friend std::istream& operator>>(std::istream& is, modint& m) noexcept { is >> m.x; m.x %= mod; if (m.x < 0) m.x += mod; return is; } friend ostream& operator<<(ostream& os, const modint& m){ os << m.x; return os; } }; using mint = modint; struct SegmentTree{ ll n; vector dat; SegmentTree(ll n_){ n = 1; while(n < n_) n*=2; dat.resize(2*n, 0); } void update(ll k, ll a){ k += n-1; dat[k] += a; while(k > 0){ k = (k-1)/2; dat[k] = dat[2*k+1]+dat[2*k+2]; } } // the minimun element of [a, b) ll query(ll a, ll b){return query_sub(a, b, 0, 0, n);} ll query_sub(ll a, ll b, ll k, ll l, ll r){ if(r <= a || b <= l){ return 0; }else if(a <= l && r <= b){ return dat[k]; }else{ ll vl = query_sub(a, b, 2*k+1, l, (l+r)/2); ll vr = query_sub(a, b, 2*k+2, (l+r)/2, r); return vl+vr; } } }; int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); ll n, m; cin >> n >> m; ll rn = n-m; vector p(n, -1); vector check(n, false); vector reserve(m); rep(i, m){ ll v, k; cin >> v >> k; v--; k--; p[k] = v; check[v] = true; reserve[i] = {k, v}; } vector lv(n, 0), rv(n, 0); if(p[0]==-1) lv[0]++; for(ll i=1; i=0; i--) rv[i] = rv[i+1]+(p[i]==-1); vector g_cnt(n, 0), l_cnt(n, 0); l_cnt[0] = !check[0]; for(ll i=1; i=0; i--) g_cnt[i] = g_cnt[i+1]+!check[i]; vector perm(n+1, 1); for(ll i=1; i<=n; i++) perm[i] = perm[i-1]*i; mint ans = perm[rn]*rn*(rn-1)/4; rep(i, n) if(p[i]!=-1){ ans += perm[rn-1]*g_cnt[p[i]]*lv[i]; ans += perm[rn-1]*l_cnt[p[i]]*rv[i]; } sort(all(reserve)); ll original_inv = 0; SegmentTree ST(n); rep(i, m){ ll v = reserve[i].se; original_inv += ST.query(v+1, n); ST.update(v, 1); } ans += perm[rn]*original_inv; cout << ans << endl; }