t=gets.to_i
r=0...n=gets.to_i
a=r.map{gets.to_i}
d=[0]
(1..1<<n).map{|h|d<<r.map{|i|h[i]>0?(x=d[h^1<<i];y=t-x%t;y<(b=a[i])?x+b+y:x+b):1e9}.min}
p (d[-2]+t-1)/t