import std.conv, std.functional, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.numeric, std.range, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum MO = 10L^^9 + 7;

int N, M, K;
int[] L, R;

void main() {
  try {
    for (; ; ) {
      N = readInt();
      M = readInt();
      K = readInt();
      L = new int[M];
      R = new int[M];
      foreach (i; 0 .. M) {
        L[i] = readInt() - 1;
        R[i] = readInt();
      }
      
      auto dp = new long[N];
      dp[0] = 1;
      foreach (k; 0 .. K) {
        auto dpSum = new long[N + 1];
        foreach (x; 0 .. N) {
          dpSum[x + 1] = (dpSum[x] + dp[x]) % MO;
        }
        dp = new long[N + 1];
        foreach (i; 0 .. M) {
          const c = (dpSum[R[i]] - dpSum[L[i]]) % MO;
          dp[L[i]] += c;
          dp[R[i]] -= c;
        }
        foreach (x; 1 .. N + 1) {
          dp[x] = (dp[x] + dp[x - 1]) % MO;
        }
        assert(dp[N] == 0);
      }
      const ans = (dp[N - 1] % MO + MO) % MO;
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}