import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.PrintWriter; import java.math.BigDecimal; import java.text.DecimalFormat; import java.util.AbstractMap; import java.util.ArrayDeque; import java.util.ArrayList; import java.util.Arrays; import java.util.Comparator; import java.util.Deque; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Queue; import java.util.Set; import java.util.TreeMap; import java.util.TreeSet; import static java.util.Comparator.*; public class Main { public static void main(String[] args) { InputStream inputStream = System.in; OutputStream outputStream = System.out; MyInput in = new MyInput(inputStream); PrintWriter out = new PrintWriter(outputStream); Solver solver = new Solver(); solver.solve(1, in, out); out.close(); } // ====================================================================== // static class Solver { int MOD = 1000000007; long[][] dp; public void solve(int testNumber, MyInput in, PrintWriter out) { int N = in.nextInt(); int M = in.nextInt(); int K = in.nextInt(); int[] L = new int[M]; int[] R = new int[M]; for(int i=0; i < M; i++) { L[i] = in.nextInt(); R[i] = in.nextInt(); } dp = new long[K+1][N+1]; // for(int i=1; i < K+1; i++) // for(int j=0; j < N+1; j++) // dp[i][j] = -1; long wk; dp[0][1] = 1; // 初期値 for(int i=0; i < K; i++) { // 移動回数 for(int j=0; j < M; j++) { // エレベータ数 wk = 0; for(int k=L[j]; k <= R[j]; k++) { // エレベータの止まる階数分 wk += dp[i][k]; wk %= MOD; } for(int k=L[j]; k <= R[j]; k++) { // エレベータの止まる階数分 dp[i+1][k] += wk; dp[i+1][k] %= MOD; } } } out.println(dp[K][N]); } } static class PPP { public int key, val; public PPP(int key, int val) { this.key = key; this.val = val; } public int getKey() { return key; } public void setKey(int key) { this.key = key; } public int getVal() { return val; } public void setVal(int val) { this.val = val; } } // ====================================================================== static class Pair extends AbstractMap.SimpleEntry { /** serialVersionUID. */ private static final long serialVersionUID = 6411527075103472113L; public Pair(final K key, final V value) { super(key, value); } } static class MyInput { private final BufferedReader in; private static int pos; private static int readLen; private static final char[] buffer = new char[1024 * 8]; private static char[] str = new char[500 * 8 * 2]; private static boolean[] isDigit = new boolean[256]; private static boolean[] isSpace = new boolean[256]; private static boolean[] isLineSep = new boolean[256]; static { for (int i = 0; i < 10; i++) { isDigit['0' + i] = true; } isDigit['-'] = true; isSpace[' '] = isSpace['\r'] = isSpace['\n'] = isSpace['\t'] = true; isLineSep['\r'] = isLineSep['\n'] = true; } public MyInput(InputStream is) { in = new BufferedReader(new InputStreamReader(is)); } public int read() { if (pos >= readLen) { pos = 0; try { readLen = in.read(buffer); } catch (IOException e) { throw new RuntimeException(); } if (readLen <= 0) { throw new MyInput.EndOfFileRuntimeException(); } } return buffer[pos++]; } public int nextInt() { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); int i = 0; int ret = 0; if (str[0] == '-') { i = 1; } for (; i < len; i++) ret = ret * 10 + str[i] - '0'; if (str[0] == '-') { ret = -ret; } return ret; } public long nextLong() { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); int i = 0; long ret = 0L; if (str[0] == '-') { i = 1; } for (; i < len; i++) ret = ret * 10 + str[i] - '0'; if (str[0] == '-') { ret = -ret; } return ret; } public String nextString() { String ret = new String(nextDChar()).trim(); return ret; } public char[] nextDChar() { int len = 0; len = reads(len, isSpace); char[] ret = new char[len + 1]; for (int i=0; i < len; i++) ret[i] = str[i]; ret[len] = 0x00; return ret; } public char nextChar() { while (true) { final int c = read(); if (!isSpace[c]) { return (char) c; } } } int reads(int len, boolean[] accept) { try { while (true) { final int c = read(); if (accept[c]) { break; } if (str.length == len) { char[] rep = new char[str.length * 3 / 2]; System.arraycopy(str, 0, rep, 0, str.length); str = rep; } str[len++] = (char) c; } } catch (MyInput.EndOfFileRuntimeException e) { } return len; } static class EndOfFileRuntimeException extends RuntimeException { } } }