#include <bits/stdc++.h>
using namespace std;
ifstream fin ( "grupuri.in" );
ofstream fout ( "grupuri.out" );
int k, n;
int a[100005];
int ok ( int x ) {
    int s = 0;

    for ( int i = 1; i <= n; i++ )
        if ( a[i] > k )
            s += k;
        else s += a[i];

    if ( s >= x * k )
        return 1;

    return 0;
}
int cauta ( int k ) {
    int l = 0, r = n + 1;

    while ( r - l > 1 ) {
        int mid = ( l + r ) / 2;

        if ( ok ( mid ) )
            l = mid;
        else r = mid;
    }

    return r;
}
int main() {
    fin >> k >> n;

    for ( int i = 1; i <= n; i++ )
        fin >> a[i];

    sort ( a + 1, a + n + 1 );
    fout << cauta ( k );
    return 0;
}