program parfenie;
var f,g:text;sum,med:real;
a,b,c,medt,j:integer;
i,k1,k:byte;
s:string;
type
caractere= set of char;
Litmari='A'..'Z';
litmici='a'..'z';
begin
assign(f,'text.in');reset(f);
assign(g,'text.out');rewrite(g);
read(f,s);
for i:=1 to length(s) do begin
                         if s[i] in ['A'..'Z'] then inc(k);
                         if s[i] in ['a'..'z'] then inc(k);
                         end;
for j:=1 to length(s) do if (s[j]='')or(s[j]=',') then inc(k1);
sum:=k;
med:=sum/k1;
medt:=trunc(med);
write(g,medt);
close(f);
close(g);
end.