import sys
def MI(): return map(int,sys.stdin.readline().rstrip().split())


N,M,K = MI()
LR = [tuple(MI()) for _ in range(M)]
mod = 10**9+7

A = [0]*(N+2)
SA = [1]*(N+2)
SA[0] = 0
for _ in range(K):
    for i in range(M):
        L,R = LR[i]
        x = SA[R]-SA[L-1]
        A[L] += x
        A[R+1] -= x
    SA = [0]*(N+2)
    for i in range(1,N+2):
        SA[i] = A[i]+SA[i-1]
        SA[i] %= mod
    for i in range(1,N+2):
        SA[i] += SA[i-1]
        SA[i] %= mod
    A = [0]*(N+2)

print(SA[N]-SA[N-1])