`@` Pascal`:`

uses crt;
var
    i,k,n : longint;
    s : string;
    result : boolean;
begin
clrscr;
    n := 1;
    k := 0;
    readln(s);
    while k = 0 do
        begin
        if s[n] in ['A'..'Z'] then k := 1
            else
        if s[n] in ['a'..'z'] then k := 2
            else inc(n);
        end;
    for i := 1 to length(s) do
        begin
        result := false;
        if k mod 2 = 1 then
            begin
            if s[i+1] in ['A'..'Z'] then s[i+1] := chr(ord(s[i+1])+32);
            inc(k);
            result := true;
            end;
        if (k mod 2 = 0) and (result = false ) then
            begin
            if s[i+1] in ['a'..'z'] then s[i+1] := upcase(s[i+1]);
            inc(k);
            end;
        end;
    writeln(s);
end.