Problem:
Score : 500 points

Problem Statement

Given are N positive integers A_1,...,A_N.

Consider positive integers B_1, ..., B_N that satisfy the following condition.

Condition: For any i, j such that 1 \leq i < j \leq N, A_i B_i = A_j B_j holds.

Find the minimum possible value of B_1 + ... + B_N for such B_1,...,B_N.

Since the answer can be enormous, print the sum modulo (10^9 +7).

Constraints

1 \leq N \leq 10^4

1 \leq A_i \leq 10^6

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A_1 ... A_N

Output

Print the minimum possible value of B_1 + ... + B_N for B_1,...,B_N that satisfy the condition, modulo (10^9 +7).

Sample Input 1

3
2 3 4

Sample Output 1

13

Let B_1=6, B_2=4, and B_3=3, and the condition will be satisfied.

Sample Input 2

5
12 12 12 12 12

Sample Output 2

5

We can let all B_i be 1.

Sample Input 3

3
1000000 999999 999998

Sample Output 3

996989508

Print the sum modulo (10^9+7).

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

// using System.Numerics;
using System.Runtime.CompilerServices;
using System.Diagnostics;
using ll=System.Int64;
using static Contest_E.Lib_IO;
using static Contest_E.Lib_Minifunc;



public class Contest_E
{

	public static void Main() {
		checked{
			long  n;
			Lib_IO.rm(out n);
			ll[] a;
			ra(out a);

			Dictionary<long,long>[] ps = new Dictionary<long, ll>[n];
			Dictionary<long,long> lcm = new Dictionary<ll, ll>();
			for (int i = 0; i < n; i++)
			{
				ps[i] = ElementCount(PrimeFactor(a[i]));
				foreach(var e in ps[i]){
					if(!lcm.ContainsKey(e.Key)) lcm[e.Key]=0;
					if(lcm[e.Key]<e.Value) lcm[e.Key]=e.Value;
				}
			}

			ModInt mlcm = new ModInt(1,MOD1);
			foreach(var e in lcm) mlcm *= Pow(e.Key,e.Value,MOD1); 

			ModInt ans = new ModInt(0,MOD1);
			for (int i = 0; i < n; i++)
			{
				ans+=(mlcm/a[i]);
			}


			Lib_IO.wm(ans.Value);
		}
	}
public struct ModInt {
	public long Value, Modulo;
//	public System.Numerics.BigInteger Value, Modulo;

	public ModInt(long value) : this(value, long.MaxValue) {}
	public ModInt(long value, long modulo) {
//	public ModInt(System.Numerics.BigInteger value, System.Numerics.BigInteger modulo) {
		this.Modulo = modulo;
		this.Value = value >= 0 ? value % modulo : (modulo - (-value) % modulo) % modulo;
	}

	public static implicit operator ModInt(long v) => new ModInt(v, 1000000007L);
	public static ModInt operator-(ModInt a) => new ModInt(-1*a.Value, a.Modulo); 
	public static ModInt operator+(ModInt a, ModInt b) => new ModInt(a.Value + b.Value, a.Modulo); 
	public static ModInt operator-(ModInt a, ModInt b) => new ModInt(a.Value - b.Value, a.Modulo); 
	public static ModInt operator*(ModInt a, ModInt b) => new ModInt(a.Value * b.Value, a.Modulo); 
	public static ModInt operator/(ModInt a, ModInt b) => a * b.Inverse(); 
	public static bool operator==(ModInt a, ModInt b) => a.Equals(b); 
	public static bool operator!=(ModInt a, ModInt b) => !a.Equals(b); 

	public ModInt Inverse() {
		long a = this.Value, b = this.Modulo, u = 1, v = 0, t, s;
//		System.Numerics.BigInteger a = this.Value, b = this.Modulo, u = 1, v = 0, t, s;
		while(b > 0) {
			t = a / b;
			s = a - t * b; a = b; b = s;
			s = u - t * v; u = v; v = s;
		}
		return new ModInt(u, this.Modulo);
	}

	public ModInt Pow(long n) {
		ModInt ret = new ModInt(1, this.Modulo);
		ModInt mul = this;
		while(n > 0) {
			if((n & 1)==1) ret *= mul;
			mul *= mul;
			n >>= 1;
		}
		return ret;
	}

	public override bool Equals(object obj) {
		if (!(obj is ModInt)) throw new ArgumentException("Object is not a ModInt");
		return Equals((ModInt)obj);   
	}
	public bool Equals(ModInt p) => (this.Value == p.Value);
	public override int GetHashCode() => (int)(this.Value ^ this.Modulo);
	public override string ToString() => this.Value.ToString();

}

	public static long Pow(long x, long n, long m=long.MaxValue) {
		long ans = 1;
		while (n > 0) {
			if ((n & 1) == 1) ans = (ans * x) % m;
			x = (x * x) % m;
			n >>= 1; 
		}
		return ans;
	}
	public static long[] PrimeFactor(long n) {
		var ret = new List<long>();
		if (n < 2) return ret.ToArray();
		while ((n & 1) == 0) {
			ret.Add(2);
			n >>= 1;
		}
		while ((n % 3) == 0) {
			ret.Add(3);
			n /= 3;
		}
		long sqi = Convert.ToInt64(Math.Sqrt(n));
		while(sqi*sqi<=n) sqi++;
		for (long i = 5, f = 2; i < sqi; i += f, f ^= 6) {
			while ((n % i) == 0) {
				ret.Add(i);
				n /= i;
			}
			if(n==1) break;
		}
		if(1<n) ret.Add(n);
		return ret.ToArray();
	}

	public static Dictionary<T,long> ElementCount<T>(IEnumerable<T> a, long order=0) where T : IComparable<T> {
		var d = new Dictionary<T, long>();
		foreach (var e in a) {
			if(!d.ContainsKey(e)) d[e] = 0;
			d[e]++;
		}

		return d;
	}









#region BaseModule


public static class Lib_Minifunc{
	[MethodImpl(256)] public static void swap1<T>(ref T a, ref T b) { T t = a; a = b; b = t; }
	[MethodImpl(256)] public static void swap2<T>(ref T a, ref T b) where T : IComparable { if (a.CompareTo(b)==1) swap1(ref a, ref b); }  // b の方が小さければ交換
	[MethodImpl(256)] public static bool chmin<T>(ref T a, T b) where T : IComparable { if (a.CompareTo(b)== 1) { a = b; return true; } return false; }  // b の方が小さければ a を更新
	[MethodImpl(256)] public static bool chmax<T>(ref T a, T b) where T : IComparable { if (a.CompareTo(b)==-1) { a = b; return true; } return false; }  // b の方が大きければ a を更新
	[MethodImpl(256)] public static bool inside(long i, long n) => (0<=i&&i<n);
	[MethodImpl(256)] public static bool inside(long x, long y, long w, long h) => (inside(x,w)&&inside(y,h));
	[MethodImpl(256)] public static T min<T>(params T[] a) where T : IComparable => a.Min();
	[MethodImpl(256)] public static T max<T>(params T[] a) where T : IComparable => a.Max();
	[MethodImpl(256)] public static long mod(long a, long m=MOD1) { var v = a%m; return (v<0?v+m:v); }
	[MethodImpl(256)] public static long ceiling(long a, long b) => (a%b==0?a/b:a/b+1);	// 整数商の切り上げ
	[MethodImpl(256)] public static P<T,U> initp<T,U>(T a,U b) => new P<T,U>(a,b);
	[MethodImpl(256)] public static P<T,U,V> initp<T,U,V>(T a,U b,V c) => new P<T,U,V>(a,b,c);
	[MethodImpl(256)] public static P<T,U,V,W> initp<T,U,V,W>(T a,U b,V c,W d) => new P<T,U,V,W>(a,b,c,d);
	public static T[][] initm<T>(long len1,long len2,T val) where T : struct { var m = new T[len1][]; for (int i=0;i<m.Length;i++) m[i] = Enumerable.Repeat(val,(int)len2).ToArray(); return m; }
	public static T[][][] initm<T>(long len1,long len2,long len3,T val) where T : struct { var m = new T[len1][][]; for (int i=0;i<m.Length;i++) m[i] = initm(len2,len3,val); return m; }
	public const long MOD1 = 1000000007; // 10^9+7
	public const double EPS1 = 1e-8;
	public const long INF1 = 1000000000000000;  // 10^15
}

public struct P<T,U>
{
	public T A; public U B;
	public P(T a,U b) { A = a; B = b; }
	public static implicit operator KeyValuePair<T,U>(P<T,U> a) => new KeyValuePair<T,U>(a.A,a.B);
	public static implicit operator P<T,U>(KeyValuePair<T,U> a) => new P<T,U>(a.Key,a.Value);
}
public struct P<T,U,V>
{
	public T A; public U B; public V C;
	public P(T a,U b,V c) { A = a; B = b; C = c; }
}
public struct P<T,U,V,W>
{
	public T A; public U B; public V C; public W D;
	public P(T a,U b,V c,W d) { A = a; B = b; C = c; D = d; }
}

public static class Lib_IO
{
	class Prt : System.IO.StreamWriter
	{
		public override IFormatProvider FormatProvider { get { return System.Globalization.CultureInfo.InvariantCulture; } }
		public Prt(System.IO.Stream s) : base(s,new UTF8Encoding(false,true)) {}
		public Prt(System.IO.Stream s,Encoding e) : base(s,e) {}
	}
	static Prt sw = new Prt(Console.OpenStandardOutput());
	static char[] sp = new char[] {' '};
	[MethodImpl(256)] static bool eq<T,U>() => typeof(T).Equals(typeof(U));
	[MethodImpl(256)] static T ct<T,U>(U a) => (T)Convert.ChangeType(a,typeof(T));
	[MethodImpl(256)] static T cv<T>(string s) =>
		eq<T,int>()	? ct<T,int>(int.Parse(s))
	  : eq<T,long>()   ? ct<T,long>(long.Parse(s))
	  : eq<T,double>() ? ct<T,double>(double.Parse(s,System.Globalization.CultureInfo.InvariantCulture))
	  : eq<T,char>()   ? ct<T,char>(s[0])
					   : ct<T,string>(s);
	public static string[] rm<T>(out T a) {
		var z = Console.ReadLine().Split(sp,StringSplitOptions.RemoveEmptyEntries); 
		a = cv<T>(z[0]);
		return z;
	}
	public static string[] rm<T,U>(out T a,out U b) {
		var z = rm<T>(out a); 
		b = cv<U>(z[1]);
		return z;
	}
	public static string[] rm<T,U,V>(out T a,out U b,out V c) {
		var z = rm<T,U>(out a,out b); 
		c = cv<V>(z[2]);
		return z;
	}
	public static string[] rm<T,U,V,W>(out T a,out U b,out V c,out W d) {
		var z = rm<T,U,V>(out a,out b,out c); 
		d = cv<W>(z[3]);
		return z;
	}
	public static string[] rm<T,U,V,W,X>(out T a,out U b,out V c,out W d,out X e) {
		var z = rm<T,U,V,W>(out a,out b,out c,out d); 
		e = cv<X>(z[4]);
		return z;
	}
	public static string[] rm<T,U,V,W,X,Y>(out T a,out U b,out V c,out W d,out X e,out Y f) {
		var z = rm<T,U,V,W,X>(out a,out b,out c,out d,out e); 
		f = cv<Y>(z[5]);
		return z;
	}
	public static string[] ra<T>(out T[] a) {		
		var z = Console.ReadLine().Split(sp,StringSplitOptions.RemoveEmptyEntries);
		a = z.Select(cv<T>).ToArray();
		return z;
	}
	public static string[][] rl<T>(long n,out T[] a) {
		a = new T[n];
		var y = new string[n][];
		for(int i=0;i<n;i++) y[i] = rm(out a[i]);
		return y;
	}
	public static string[][] rl<T,U>(long n,out P<T,U>[] a) {
		a = new P<T,U>[n];
		var y = new string[n][];
		for(int i=0;i<n;i++) {
			T o; U p;
			y[i] = rm(out o,out p);
			a[i] = new P<T,U>(o,p);
		}
		return y;
	}
	public static string[][] rl<T,U,V>(long n,out P<T,U,V>[] a) {
		a = new P<T,U,V>[n];
		var y = new string[n][];
		for(int i=0;i<n;i++) {
			T o; U p; V q;
			y[i] = rm(out o,out p,out q);
			a[i] = new P<T,U,V>(o,p,q);
		}
		return y;
	}
	public static string[][] rl<T,U,V,W>(long n,out P<T,U,V,W>[] a) {
		a = new P<T,U,V,W>[n];
		var y = new string[n][];
		for(int i=0;i<n;i++) {
			T o; U p; V q; W r;
			y[i] = rm(out o,out p,out q,out r);
			a[i] = new P<T,U,V,W>(o,p,q,r);
		}
		return y;
	}
	public static string[][] rx<T>(long n,out T[][] a) {
		a = new T[n][];
		var y = new string[n][];
		for(int i=0;i<n;i++) y[i] = ra(out a[i]);
		return y;
	}

	static void wwp(Action act){
		sw.AutoFlush = false;
		Console.SetOut(sw);
		act();
		Console.Out.Flush();
		sw.AutoFlush = true;
		Console.SetOut(sw);
	}
	[MethodImpl(256)] static string wfm(Type t) =>t.Equals(typeof(double)) ? "{0:F10}" : "{0}";
	public static void wm(params object[] a) {
		wwp(()=>{
			for(int i=0;i<a.Length;i++) {
				var f = wfm(a[i].GetType()) + ((i<a.Length-1) ? " " : Environment.NewLine);
				Console.Write(f,a[i]);
			}
		});
	}
	public static void wa<T>(IList<T> a) {
		wwp(()=>{
			var f = wfm(typeof(T));
			var g = f + " ";
			var h = f + Environment.NewLine;
			for(int i=0;i<a.Count;i++) Console.Write(((i<a.Count-1) ? g : h),a[i]);
		});
	}
	public static void wl<T>(IList<T> a) {
		wwp(()=>{
			var f = wfm(typeof(T)) + Environment.NewLine;
			foreach(T x in a) Console.Write(f,x);
		});
	}
}

#endregion



}