from functools import reduce

MOD = 1_000_000_007

def _value_of_S_reduce(x:int,y:int)->int:
    return (x+y+x*y) % MOD

def value_of_S(l:list)->int:
    return reduce(_value_of_S_reduce,l)
    
if __name__=='__main__':
    _ = input()
    print(value_of_S(list(map(int,input().split()))))