#include <fstream>

#include <algorithm>

#include <cmath>
using namespace std;

ifstream cin ("transport.in");
ofstream cout ("transport.out");

 int v[16001];
int main()
{
    int n, k;
    cin >> n >> k;
    int maxi = -1;
    int s = 0;
    for(int i = 0; i<n; i++){
        cin>> v[i];
        if(v[i]>maxi){
            maxi = v[i];
        }
        s += v[i];
    }
    int cnt, sol;
    s = s - maxi;

    int st, dr;
    st = maxi;
    dr = s;
    int m;
    while(st<dr){
        m = (st+dr)/2;
        if(k <= m){
            sol = m;
            dr = m-1;
        }
        else{
            st = m+1;
        }
    }
    cout << sol; // ?

    return 0;
}