from itertools import accumulate
Q = 10**9 + 7
N, M, K = map( int, input().split())
I = [ tuple( map( int, input().split())) for _ in range(M)]
dp = [ [0]*(N+2) for _ in range(K+1)]
dp[0][1] = 1
for k in range(K):
    dp[k] = list( map( lambda x:x%Q, accumulate( dp[k])))
    for i in range(M):
        l, r = I[i]
        c = dp[k][r] - dp[k][l-1]
        dp[k+1][l] += c
        dp[k+1][r+1] -=c
    dp[k+1] = list( map( lambda x: x%Q, accumulate(dp[k+1])))
print(dp[K][N])