import strutils, sequtils

const mo = 1000000000 + 7
proc add(a: var int64, b: int64) =
  a += b
  if a >= mo:
    a -= mo
proc sub(a: var int64, b: int64) =
  a -= b
  if a < 0:
    a += mo

proc main() =
  let
    nmk = stdin.readLine.strip.split.map(parseInt)
    (n, m, k) = (nmk[0], nmk[1], nmk[2])
    lr = (0..<m).mapIt(stdin.readLine.strip.split.map(parseInt))

  var dp = newSeqWith(k + 1, newSeq[int64](n + 1))
  dp[0][0] = 1
  for i in 0..<k:
    for j in 0..<n:
      for s in lr:
        if s[0] - 1 <= j and j < s[1]:
          add(dp[i + 1][s[0] - 1], dp[i][j])
          sub(dp[i + 1][s[1]], dp[i][j])
    for j in 0..<n:
      add(dp[i + 1][j + 1], dp[i + 1][j])

  echo dp[k][n - 1]
main()