#!/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())
LR = np.array(read().split(), np.int32)
L = LR[::2]
R = LR[1::2]
L.flags.writeable = False
R.flags.writeable = False

# %%
dp = np.zeros(N + 2, np.int64)
dp[1] = 1
for _ in range(K):
    newdp = np.zeros_like(dp)
    np.cumsum(dp, out=dp)
    dp %= MOD
    x = dp[R] - dp[L - 1]
    np.add.at(newdp, L, x)
    np.add.at(newdp, R + 1, -x)
    np.cumsum(newdp, out=newdp)
    newdp %= MOD
    dp = newdp

# %%
print(dp[N])