def scan; gets.split.map(&:to_i); end

# abababa
def func(n)
    m = (n+1) / 2
    k = m*(m-1)-m+1
    (n.even? ? k*2 : k) + n
end

n = gets.to_i
iwi = ['a','b']

offset = 0
while n > 3

    # binary search
    c = nil
    l = 0; h = 100000
    while l < h
        c = (l+h+1)/2;
        if (n < func(c))
            h = c-1
        else
            l = c
        end
    end
    
    k = l
    n -= func(l)
    
    print ((iwi[0]+iwi[1])*((k)/2))[offset..-1]
    if k.odd?
        print iwi[0]
        iwi[1].succ!
        offset = 1
    else
        iwi[0] = iwi[1].clone
        iwi[1].succ!
        offset = 1
    end
end

print 'xyz'[0..(n-1)] if 0 < n