#!/bin/python

import sys


n = int(raw_input().strip())
m = map(int, raw_input().strip().split(' '))
# your code goes here
tot=0
if n<=2:
    tot=1
else:
    for i in range(n):
        #print (n-i)**i
        tot+= (n-i)**i

print tot%(10**9+7)