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