J - Weird Sanchola

#include<bits/stdc++.h>
#include<string>
#include<vector>

using namespace std;

typedef long long int ll;
typedef long double ld;
typedef unsigned long long int ull;
typedef long long li;

#define ms(x,a) memset(x,a,sizeof(x))
#define forn(i, n) for (int i = 0; i < int(n); i++)
#define pi      acos(0.0)*2 // 3.1415926535897932
#define mx      1000000007
#define mod     1000000007
#define base    10000007
#define pb      push_back
#define mx1     10001000

vector<ll>prm;

void inOut();
using namespace std;

bool assigned[mx];

bool prime_num(int i)
{
    if(i < 2) return false;
    if(i == 2) return true;
    if(i%2 == 0) return false;
    return assigned[i] == false;
}
void sieve(int p)
{
    for(int i=3; i*i<=p; i+=2)
    {
        if(assigned[i] == false)
        {
            for(int j=i*i; j<=p; j+=(i+i))
             {
                 assigned[j] = true;
             }
        }
    }
}
int main()
{
    inOut();
    sieve(mx);
    ll i,j,k,l,q,n,m;
    string s;

    cin>>n;
    ll a[n+2];

    for(i=0; i<n; i++)
    {
        cin>>a[i];
        if(!assigned[a[i]-1])prm.pb(a[i]);
    }

    sort(a, a+n);
    sort(prm.begin(), prm.end());
    ll sum = 0, lprm;
    ll sz = prm.size();

    for(i=sz-1; i>=0; i--)
        if(prm[i]<a[n-1])
        {
            lprm = prm[i]; break;
        }

    for(i=n-1; i>=0; i--)
    {
        if(a[i] == lprm)
            continue;
        else
            sum += abs(a[i] - lprm);
    }

    cout<<sum<<endl;

    return 0;
}

void inOut()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    #ifndef ONLINE_JUDGE
        freopen("input.txt", "r", stdin);
        //freopen("output.txt", "w", stdout);
    #endif
}