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