def encryption(s):
    # Write your code here
    n = len(s)
    x = math.sqrt(n)
    # nr = math.floor(1x)
    nc = math.ceil(x)
    # print(n, nc)

    i = 0
    j = 0
    q = []
    for _ in range(n):
        if i+j > n-1:
            q.append(' ')
            j += 1
            i = 0
        q.append(s[i+j])
        i += nc
        
    return ''.join(q)