program inf;
var f,g:Text;
    s,s1:String;
    n1,n2:integer;
begin
    assign (f,'text.in'); reset (f);
    assign (g,'text.out'); rewrite (g);
    readln (f,s);
    n1:=0; n2:=-1;
    s:=s+' ';     s1:='abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    repeat
             while pos(s[1],s1)=0 do
                 if s='' then
                    break
                    else
                delete(s,1,1);
             while pos(s[1],s1)<>0 do
                begin
                    n1:=n1+1;
                    delete(s,1,1);
                end;
                n2:=n2+1;
    until s='';
    writeln (g,n1 div n2);
    close (f); close (g);
end.