N, M, K = map(int, input().split())
ele = [list(map(int, input().split())) for _ in range(M)]

dp = [0]*(N+1)
dp[0] = 1
dp[1] = -1
mod = 10**9+7
for i in range(K):
    for j in range(N):
        dp[j+1] += dp[j]
        dp[j+1] %= mod
    for j in range(N-1):
        dp[j+1] += dp[j]
        dp[j+1] %= mod
    ndp = [0]*(N+1)
    for l, r in ele:
        num = dp[r-1] if l==1 else dp[r-1]-dp[l-2]
        num %= mod
        ndp[l-1] += num
        ndp[l-1] %= mod
        ndp[r] -= num
        ndp[r] %= mod
    dp = ndp
for i in range(N):
    dp[i+1] += dp[i]
    dp[i+1] %= mod
print(dp[-2])