# https://yukicoder.me/problems/no/801

MOD=  10 ** 9 + 7

def main():
    N, M, K = map(int, input().split())
    lr = []
    for _ in range(M):
        l, r = map(int, input().split())
        lr.append((l - 1, r - 1))

    dp = [0] * N
    dp[0] = 1
    cum_dp = [0] * N
    c = 0
    for i in range(N):
        c += dp[i]
        cum_dp[i] = c

    for _ in range(K):
        new_dp0 = [0] * (N + 1)

        for l,r in lr:
            if l == 0:
                x = cum_dp[r]
            else:
                x = (cum_dp[r] - cum_dp[l - 1]) % MOD

            new_dp0[l] += x
            new_dp0[l] %= MOD
            new_dp0[r + 1] -= x
            new_dp0[r +1] %= MOD
        
        c = 0
        for j in range(N + 1):
            c += new_dp0[j]
            c %= MOD
            new_dp0[j] = c
        
        dp = new_dp0
        c = 0
        for i in range(N):
            c += dp[i]
            cum_dp[i] = c
    
    print(dp[N - 1])








if __name__ == "__main__":
    main()