program aa;

var

s1:string;

chuan:char;

a,b,c,d,e,n:integer;

yuan,mi,cun:array[0..10000] of string;

zhen:array[0..1000,1..100] of string;

begin

read(s1);

a:=length(s1);

while a>0 do

begin

b:=trunc(sqrt(a));

for c:=1 to b do

for d:=1 to b do

zhen[c,d]:=s1[(c-1)*b+d+e];

n:=e;

for c:=1 to b do

for d:=1 to b do

e:=(c-1)*b+d;

e:=e+n;

for c:=1 to b do

for d:=1 to b do

write(zhen[d,c]);

a:=a-b*b;

end;

end.