#Coin Changing Problem

n,m = STDIN.gets.split(" ").collect{|e| e.to_i}
ds = STDIN.gets.split(" ").collect{|e| e.to_i}

#n = 55
#m = 4
#@ds = [1,5,10,50]
#@dp = Array.new(m,Array.new(n))
@max = m
def rec(index,left)
#    [index,left].each do |e|
#       print e,"," 
#    end
#    puts ""
    return 0 if left == 0
    return 50000 if index == @max
    return @dp[index][left] unless @dp[index][left] == nil

    
    v1 = rec(index + 1, left - @ds[index]) + 1 # include
    v2 = rec(index + 1, left) # not include
    v = [v1,v2].min

    @dp[index][left] = v
    return v
end

puts rec(0,n)