#include<bits/stdc++.h>
using namespace std;
int main(){
	int  n,m=99;
	cin>>n;
	int a[n][m];
	for(int i=0;i<n;i++){
		a[i][0] = 1;
		int k;
		cin>>k;//2
		k = k -1;
		for(int j=1;j<m;j++){
			for(int p=0;p<k;p++){
				a[i][j+p] = 0;
			}
			j= j + k;
			a[i][j] = 1; 
		}
	} 
	int j;
	for( j=1;j<m;j++){
		bool f = true;//假定列上每一个数都是1 
		for(int i=0;i<n;i++){
			if(a[i][j]!=1){
				f  = false;
			}
		}
		if(f == true){
			break;
		}
	}
	cout<<j+1;
	return 0;
}

/**************************************************************
	Problem: 1333
	User: admin
	Language: C++
	Result: Wrong Answer
****************************************************************/