#include <fstream>
#define ll long long
using namespace std;
int k,n,v[100005];
bool check(ll grupuri)
{
    ll sum=0;
    for(int i=1;i<=n;i++)
    sum+=min(k,v[i]);
    if(sum>=grupuri*k)
        return 1;
    return 0;
}
ll cautbin(int n,int k)
{
    ll st=1,dr=1000000000005,mid,sol;
    while(st<=dr)
    {
        mid=(st+dr)/2;
        if(check(mid)==1)
        {
            sol=mid;
            st=mid+1;
        }
        else
            dr=mid-1;

    }
    return sol;
}
int main()
{
    ifstream cin("grupuri.in");
    ofstream cout("grupuri.out");
    cin>>k>>n;
    for(int i=1;i<=n;i++)
        cin>>v[i];
        cout<<cautbin(n,k);
    return 0;
}