//GNC
#include<iostream>
#include<string>
#include <vector>
#include <algorithm>
#include <map>
#include <set>
#include <fstream>
#include <sstream>

using namespace std;

typedef long long ll;

ll gcd(ll x, ll y)
{
  if(y == 0)  return x;
  return gcd(y, x%y);
}

ll lcm(ll x, ll y)
{
  return x / gcd(x, y) * y;
}

ll exgcd(ll a, ll b, ll& x, ll& y)
{
  if(b == 0LL){
    x = 1LL;
    y = 0LL;
    return a;
  }else{
    ll d = exgcd(b, a%b, y, x);
    y -= a / b * x;
    return d;
  }
}
/*
bool isprime(int p)
{
  switch (p) {
  case 2:
  case 3:
  case 5:
  case 7:
  case 11:
  case 13:
  case 17:
  case 19:
  case 23:
  case 29:
  case 31:
  case 37:
    return true;
  default:
    return false;
  }
}

ll chinese_remainder(ll a, ll cur_lcm, ll remind, ll modulo)
{
  ll a = exgcd(
}
*/
int main(void)
{
  int N;
  ifstream cin("moduloscope.in");
  while(cin >> N && N){
    ll current = 0;
    ll curlcm = 1;
    for(int i = 1; i <= N; ++i){
      ll mod;
      cin >> mod;
      for(;;){
	if(current % (ll)i == mod) break;
	current += curlcm;
      }
      curlcm = lcm(curlcm, (ll)i);
    }
    cout << current << endl;
  }
  return 0;
}