#!/bin/python import sys def rwh_primes2(n): # https://stackoverflow.com/questions/2068372/fastest-way-to-list-all-primes-below-n-in-python/3035188#3035188 """ Input n>=6, Returns a list of primes, 2 <= p < n """ correction = (n%6>1) n = {0:n,1:n-1,2:n+4,3:n+3,4:n+2,5:n+1}[n%6] sieve = [True] * (n/3) sieve[0] = False for i in xrange(int(n**0.5)/3+1): if sieve[i]: k=3*i+1|1 sieve[ ((k*k)/3) ::2*k]=[False]*((n/6-(k*k)/6-1)/k+1) sieve[(k*k+4*k-2*k*(i&1))/3::2*k]=[False]*((n/6-(k*k+4*k-2*k*(i&1))/6-1)/k+1) return [2,3] + [3*i+1|1 for i in xrange(1,n/3-correction) if sieve[i]] ps = rwh_primes2(1000000) def longestSequence(a): sum=0 for i in a: moves=1 j=0 while i>1 and j1: moves = moves*i+1 sum+=moves return sum if __name__ == "__main__": n = int(raw_input().strip()) a = map(long, raw_input().strip().split(' ')) result = longestSequence(a) print result