#include <cstdio>
# define DIM 10000000

#define ULL unsigned long long
using namespace std;
int i,j,k,n,a[100005],stg,dr;
ULL sum,mij,rasp;
int poz=0;
char buff[DIM];
void citire(int & numar)
{
    numar=0;
    while(buff[poz]<'0'||buff[poz]>'9')
        if(++poz==DIM) fread(buff,1,DIM,stdin),poz=0;
    while('0'<=buff[poz]&&buff[poz]<='9')
    {
        numar=numar*10+buff[poz]-'0';
        if(++poz==DIM) fread(buff,1,DIM,stdin),poz=0;
    }
}
int sol(ULL  x)
{
    int i=0;
    ULL nr=0;
    for(i=1;i<=n;i++)
        if(a[i]>x)
        nr+=x;
    else
        nr+=a[i];
    if(x*k<=nr) return 1;
    return 0;
}
int main(void)
{
    freopen("grupuri.in","r",stdin);
    freopen("grupuri.out","w",stdout);
    citire(k);
    citire(n);
    for(i=1;i<=n;i++) citire(a[i]),sum+=a[i];
    stg=1;
    dr=sum/k;
    while(stg<=dr)
    {
        mij=(stg+dr)/2;
        if(sol(mij))
            {
                rasp=mij;
                stg=mij+1;
            }
        else
            dr=mij-1;
    }
    printf("%lld",rasp);
    return 0;
}