program Project2;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var z,big,small:set of char;
  i,j:integer;
  b,t,x,k,q:boolean;
  a:array[0..501]of char;


procedure invers(a:char);
begin
if a in big then write(chr(ord(a)+32))else
write(chr(ord(a)-32))
end;

begin
assign(input,'text.in');
reset(input);
 assign(output,'text.out');
rewrite(output);
i:=0;
z:=z+['.']+['?']+['!'];
big:=big+['A'..'Z'];
small:=small+['a'..'z'];
b:=false;
t:=false;
while not eoln do
begin
inc(i);
read(a[i]);
end;
x:=true;
q:=false;
for j:=1 to i do
begin


if not(b)then
begin
if (a[j]in small)and(a[j+1]in big)then begin b:=true; k:=true; end else
if((a[j]in big)and((a[j+1])in big))then begin t:=true; b:=true end;
end;
if (b)and(not(q))then
begin
q:=true;
if ((x)and(k))or(not(x)and(t))
then invers(a[j]) else write(a[j]);
end else
if (a[j]in big)or(a[j]in small)then invers(a[j])else write(a[j]);
if a[j]in z then x:=true else x:=false;
end;
close(input);
writeln;
close(output);
end.