import java.io.*; import java.util.Arrays; import java.util.StringJoiner; import java.util.StringTokenizer; import java.util.function.Function; public class Main { static int N, M, K; static int[] L, R; public static void main(String[] args) { FastScanner sc = new FastScanner(System.in); N = sc.nextInt(); M = sc.nextInt(); K = sc.nextInt(); L = new int[M]; R = new int[M]; for (int i = 0; i < M; i++) { // [L, R), 0-origin L[i] = sc.nextInt()-1; R[i] = sc.nextInt(); } System.out.println(solve()); } static int solve() { int[] curr = new int[N]; int[] next = new int[N]; curr[0] = 1; for (int i = 0; i < K; i++) { Arrays.fill(next, 0); int[] cum = new int[N+1]; for (int j = 0; j < N; j++) { cum[j+1] = add(cum[j], curr[j]); } int[] imos = new int[N+1]; for (int j = 0; j < M; j++) { // [L, R) int cnt = sub(cum[R[j]], cum[L[j]]); imos[L[j]] += cnt; imos[L[j]] %= MOD; imos[R[j]] -= cnt; imos[R[j]] += MOD; imos[R[j]] %= MOD; } for (int j = 0; j < N; j++) { imos[j+1] += imos[j]; imos[j+1] %= MOD; } for (int j = 0; j < N; j++) { next[j] = imos[j]; } int[] t = curr; curr = next; next = t; } return curr[N-1]; } static int MOD = 1_000_000_007; static int pow(int base, long exp) { if (exp == 0) return 1; int ans = 1; base %= MOD; while (exp > 0) { if ((exp & 1) == 1) { ans = mul(ans, base); } base = mul(base, base); exp = exp >> 1; } return ans; } static int sub(int a, int b) { int c = a - b; if (c < 0) c += MOD; return c; } static int div(int a, int b) { return mul(a, pow(b, MOD - 2)); } static int add(int a, int b) { int c = a + b; if (c >= MOD) c %= MOD; return c; } static int mul(int a, int b) { long c = (long) a * b; if (c >= MOD) c %= MOD; return (int) c; } static class FermatCombination { private final int size; private final int[] factorial; // n -> factorial(n) private final int[] inverse; // n -> inverse(factorial(n)) FermatCombination(int size) { this.size = size; factorial = new int[size + 1]; inverse = new int[size + 1]; init(); } private void init() { factorial[0] = 1; factorial[1] = 1; inverse[0] = 1; inverse[1] = 1; for (int i = 2; i <= size; i++) { factorial[i] = mul(factorial[i - 1], i); inverse[i] = pow(factorial[i], MOD - 2); } } int comb(int n, int k) { if (n > size) throw new RuntimeException("wtf : size=" + size + " n=" + n); return mul(mul(factorial[n], inverse[k]), inverse[n - k]); } // 重複組み合わせ // k種類からn個選ぶ場合の数 int hcomb(int k, int n) { return comb(k + n - 1, n); } int group(int n, int g, int k) { // C(n, g) * C(n-g, g)... / k! // n! / (n-gk)! / g! ^ k / k! int ret = factorial[n]; // n! ret = mul(ret, inverse[n - g * k]); // 1 / (n-gk)! ret = mul(ret, pow(inverse[g], k)); // 1 / (g! ^ k) ret = mul(ret, inverse[k]); // 1 / k! return ret; } } @SuppressWarnings("unused") static class FastScanner { private BufferedReader reader; private StringTokenizer tokenizer; FastScanner(InputStream in) { reader = new BufferedReader(new InputStreamReader(in)); tokenizer = null; } String next() { if (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new StringTokenizer(reader.readLine()); } catch (IOException e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } String nextLine() { if (tokenizer == null || !tokenizer.hasMoreTokens()) { try { return reader.readLine(); } catch (IOException e) { throw new RuntimeException(e); } } return tokenizer.nextToken("\n"); } long nextLong() { return Long.parseLong(next()); } int nextInt() { return Integer.parseInt(next()); } int[] nextIntArray(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } int[] nextIntArray(int n, int delta) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt() + delta; return a; } long[] nextLongArray(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nextLong(); return a; } } static void writeLines(A[] as, Function f) { PrintWriter pw = new PrintWriter(System.out); for (A a : as) { pw.println(f.apply(a)); } pw.flush(); } static void writeLines(int[] as) { PrintWriter pw = new PrintWriter(System.out); for (int a : as) pw.println(a); pw.flush(); } static void writeLines(long[] as) { PrintWriter pw = new PrintWriter(System.out); for (long a : as) pw.println(a); pw.flush(); } static int max(int... as) { int max = Integer.MIN_VALUE; for (int a : as) max = Math.max(a, max); return max; } static int min(int... as) { int min = Integer.MAX_VALUE; for (int a : as) min = Math.min(a, min); return min; } static void debug(Object... args) { StringJoiner j = new StringJoiner(" "); for (Object arg : args) { if (arg instanceof int[]) j.add(Arrays.toString((int[]) arg)); else if (arg instanceof long[]) j.add(Arrays.toString((long[]) arg)); else if (arg instanceof double[]) j.add(Arrays.toString((double[]) arg)); else if (arg instanceof Object[]) j.add(Arrays.toString((Object[]) arg)); else j.add(arg.toString()); } System.err.println(j.toString()); } }