MOD = 10 ** 9 + 7

n, m, k = map(int, input().split())

elevators = [list(map(int, input().split())) for _ in range(m)]

dp = [0 for _ in range(n + 2)]
dp[1] = 1
for _ in range(k):
  s = [0 for _ in range(n + 2)]
  for i in range(1, n + 2):
    s[i] = (s[i - 1] + dp[i]) % MOD

  ndp = [0 for _ in range(n + 2)]
  for l, r in elevators:
    ndp[l] = (ndp[l] + s[r] - s[l - 1]) % MOD
    ndp[r + 1] = (ndp[r + 1] - s[r] + s[l - 1]) % MOD

  for i in range(1, n + 2):
    ndp[i] = (ndp[i - 1] + ndp[i]) % MOD

  dp = ndp

print(dp[n])