#include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using ll = long long; class range {private: struct I{int x;int operator*(){return x;}bool operator!=(I& lhs){return x ostream& operator<<(ostream& os, const pair& p){ return os << "{" << p.first << ", " << p.second << "}"; } template ostream& operator<<(ostream& os, const vector& obj) { os << "{"; for (const auto& e : obj) os << e << ", "; return os << "}"; } template ostream& operator<<(ostream& os, const set& obj) { os << "set{"; for (const auto& e : obj) os << e << ", "; return os << "}"; } template ostream& operator<<(ostream& os, const map& obj) { os << "map{"; for (const auto& e : obj) os << e << ", "; return os << "}"; } template void take(vector& vec, int n) { vec.resize(n); for (int i = 0; i < n; ++i) cin >> vec[i]; } #ifdef ONLINE_JUDGE #define dump(expr) ; #else #define dump(expr) { cerr << "\033[33m#L" << __LINE__ << ": " << expr << "\033[39m" << endl; } #endif const ll mod = 1000000007; struct mint { ll x; mint(ll x_ = 0) : x((x_ % mod + mod) % mod) {} mint operator-() const { return mint(-x); } mint &operator+=(const mint &a) { if ((x += a.x) >= mod) x -= mod; return *this; } mint &operator-=(const mint &a) { if ((x += mod - a.x) >= mod) x -= mod; return *this; } mint &operator*=(const mint &a) { (x *= a.x) %= mod; return *this; } mint operator+(const mint &a) const { mint res(*this); return res += a; } mint operator-(const mint &a) const { mint res(*this); return res -= a; } mint operator*(const mint &a) const { mint res(*this); return res *= a; } mint pow(ll t) const { if (!t) return 1; mint a = pow(t >> 1); a *= a; if (t & 1) a *= *this; return a; } mint inv() const { return pow(mod - 2); } mint &operator/=(const mint &a) { return (*this) *= a.inv(); } mint operator/(const mint &a) const { mint res(*this); return res /= a; } friend ostream &operator<<(ostream &os, const mint &m) { os << m.x; return os; } friend istream &operator>>(istream &is, mint &m) { is >> m.x; return is; } }; template struct PrefixSum { vector sums; PrefixSum(vector vs) { int n = (int)vs.size(); sums.resize(n + 1, (T)0); for (int i : range(n)) sums[i + 1] = sums[i] + vs[i]; } T sum(int i, int j) { // vs[i] + ... + vs[j] if (i > j) return (T)0; return sums[j + 1] - sums[i]; } }; namespace solver { template struct In2 { T1 a; T2 b; friend std::istream& operator>>(std::istream& is, In2& obj) { T1 t1; T2 t2; is >> t1 >> t2; obj = {t1, t2}; return is; } }; template struct In3 { T1 a; T2 b; T3 c; friend std::istream& operator>>(std::istream& is, In3& obj) { T1 t1; T2 t2; T3 t3; is >> t1 >> t2 >> t3; obj = {t1, t2, t3}; return is; } }; int n, m, k; vector> vs; void read() { cin >> n >> m >> k; take(vs, m); } using RetType = mint; RetType run() { vector dp(n); dp[0] = 1; for ([[maybe_unused]] int iter : range(k)) { vector ws(m); PrefixSum ps(dp); for (int j : range(m)) { ws[j] = ps.sum(vs[j].a - 1, vs[j].b - 1); } vector adding(n + 1); for (int j : range(m)) { adding[vs[j].a - 1] += ws[j]; adding[vs[j].b ] -= ws[j]; } vector nextdp(n); nextdp[0] = adding[0]; for (int i : range(1, n)) nextdp[i] = nextdp[i - 1] + adding[i]; dp = nextdp; } return dp[n - 1]; } } // namespace template void run(F f) { if constexpr (std::is_same_v) f(); else cout << f() << endl; } int main(int argc, char** argv) { cerr << fixed << setprecision(12); cout << fixed << setprecision(12); int testcase = 1; if (argc > 1) testcase = atoi(argv[1]); while (testcase--) { solver::read(); } run(solver::run); }