#include<stdio.h>
#define N 100001
long a[N],n,m,i,j,r,l;
unsigned long long s,t;
int main()
{freopen("grupuri.in","r",stdin);
freopen("grupuri.out","w",stdout);
scanf("%ld%ld",&n,&m),r=n;
for(i=1;i<=m;i++)
       {scanf("%ld",&a[i]);
       if(!a[i])
             l++;
       else
             s+=a[i];}
t=s/r,j=m;
while(t<a[j])
       {for(i=j;i&&a[i]>t;i--)
             s-=a[i];      
       j=m-i,r-=j;
       if(s<r||a[l+1]>=s/r)
             break;
       t=s/r;}
printf("%llu",t);
return 0;}