n, m, k = map(int, input().split())
LR = [list(map(int, input().split())) for _ in range(m)]
mod = 10**9 + 7

accumDP = [1 for _ in range(n + 1)]
accumDP[0] = 0
for _ in range(k):
    DP = [0 for _ in range(n + 1)]
    for i in range(m):
        l, r = LR[i]
        res = accumDP[r] - accumDP[l - 1]
        res %= mod
        DP[l - 1] += res
        DP[l - 1] %= mod
        DP[r] -= res
        DP[r] %= mod
    for i in range(n):
        DP[i + 1] += DP[i]
        DP[i + 1] %= mod
    accumDP = [0 for _ in range(n + 1)]
    for i in range(n):
        accumDP[i + 1] = (accumDP[i] + DP[i]) % mod
print(DP[n - 1])