#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;

#define fi first
#define se second
#define repl(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define rep(i,n) repl(i,0,n)
#define all(x) (x).begin(),(x).end()
#define dbg(x) cout<<#x"="<<x<<endl
#define mmax(x,y) (x>y?x:y)
#define mmin(x,y) (x<y?x:y)
#define maxch(x,y) x=mmax(x,y)
#define minch(x,y) x=mmin(x,y)
#define uni(x) x.erase(unique(all(x)),x.end())
#define exist(x,y) (find(all(x),y)!=x.end())
#define bcnt(x) ((x)==0?0:__builtin_popcount(x))

#define INF 1e16
#define mod 1000000007

int n;
int a[10],b[10],c[10];

int main(){
  cin>>n;
  rep(i,n)cin>>a[i];

  int S=0;
  rep(T,1<<n){
    if(bcnt(T)<=1)continue;
    int pairnum=0;
    rep(i,n)rep(j,i){
      if(((T>>i)&1)&&((T>>j)&1)){
        b[pairnum]|=1<<S;
      }
      pairnum++;
    }
    rep(i,n)if((T>>i)&1)c[i]|=1<<S;
    S++;
  }
  ll res=INF;
  rep(T,1<<S){
    bool ok=true;
    rep(i,n*(n-1)/2){
      if(bcnt(T&b[i])>1){
        ok=false;
        break;
      }
    }
    if(!ok)continue;
    ll sum=0;
    rep(i,n){
      if(bcnt(T&c[i])>a[i]){
        ok=false;
        break;
      }
      sum+=a[i]-bcnt(T&c[i]);
    }
    if(!ok)continue;
    minch(res,sum+bcnt(T));
  }
  cout<<res<<endl;
  return 0;
}

