n = gets.to_i
score = Array.new(n,0)
@free = []
n.times{|i|
    j=0;gets.chomp.chars{|c|
        case c
        when 'o';score[i]-=1
        when '-';@free<<[i,j].sort!
        end
        j+=1
    }
}

@free.uniq!

def dfs(i,score)
    if @free.size==i
        # チーム番号を保持してソート，team-Kを線形探索
        k=score[0];
        return score.sort.uniq.index(k)+1
    else
        e = @free[i]
        s = score.clone ; s[e[0]]-=1
        ra = dfs(i+1,s)
        s = score.clone ; s[e[1]]-=1
        rb = dfs(i+1,s)
        return [ra,rb].min
    end
end


p dfs(0,score)