n,m,k = map(int,input().split())
lr = [list(map(int,input().split())) for _ in range(m)]
for i in range(m):
    lr[i][0] -= 1
    lr[i][1] -= 1
MOD = 10**9+7
dp = [1]*(n+1)
for I in range(k):
    ndp = [0]*(n+1)
    for l,r in lr:
        v = dp[r] - (dp[l-1] if l else 0)
        ndp[l] += v
        ndp[l] %= MOD
        ndp[r+1] -= v
        ndp[r+1] %= MOD
    for i in range(1,n+1):
        ndp[i] += ndp[i-1]
        ndp[i] %= MOD
    dp = ndp
    if I==k-1: break
    for i in range(1,n+1):
        ndp[i] += ndp[i-1]
        ndp[i] %= MOD
print(dp[n-1]%MOD)