import sys
input = sys.stdin.readline

N, M, K = map(int, input().split())
LR = [tuple(map(int, input().split())) for _ in range(M)]
dp = [0]*N
dp[0] = 1
MOD = 10**9+7

for _ in range(K):
    acc = [0]
    
    for dpi in dp:
        acc.append((acc[-1]+dpi)%MOD)
    
    imos = [0]*(N+1)
    
    for L, R in LR:
        imos[L-1] += acc[R]-acc[L-1]
        imos[R] -= acc[R]-acc[L-1]
    
    for i in range(1, N+1):
        imos[i] += imos[i-1]
        imos[i] %= MOD
    
    dp = imos[:-1]

print(dp[-1])