#!/usr/bin/env python3.8
# %%
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import numpy as np
MOD = 10 ** 9 + 7

# %%
N, M, K = map(int, readline().split())
m = map(int, read().split())
L, R = zip(*zip(m, m))

# %%
dp = [0] * (N + 2)
dp[1] = 1
for _ in range(K):
    newdp = [0] * (N + 2)
    for i in range(1, N + 2):
        dp[i] += dp[i - 1]
    for l, r in zip(L, R):
        x = dp[r] - dp[l - 1]
        newdp[l] += x
        newdp[r + 1] -= x
    for i in range(1, N + 2):
        newdp[i] += newdp[i - 1]
        newdp[i] %= MOD
    dp = newdp

# %%
print(dp[N])