n,m,k=map(int,input().split())
dp=[[0 for i in range(3030)]for j in range(3030)]
e=[]
for i in range(m) :
    x,y=map(int,input().split())
    e.append([x,y])
mod = 1000000007
dp[0][1]=1
for i in range(k):
    for j in range(n) :
        dp[i][j+1]+=dp[i][j]
        dp[i][j+1]%=mod
    for p in e :
        dp[i+1][p[0]]+=dp[i][p[1]]-dp[i][p[0]-1]
        dp[i+1][p[1]+1]-=dp[i][p[1]]-dp[i][p[0]-1]
    for j in range(n):
        dp[i+1][j+1]+=dp[i+1][j]
        dp[i+1][j+1]%=mod
print(dp[k][n])