var f,g:text; s,t:char; na,nr,a,b,x:longint;
begin
assign(f,'text.in');reset(f);
assign(g,'text.out');rewrite(g);
readln(f,s);
a:=ord(s);
if ((a>64)and(a<91))or((a>96)and(a<123)) then na:=na+1;
t:=s;
if ((a>64)and(a<91))or((a>96)and(a<123)) then nr:=nr+1;
while not(eof(f)) do begin
      t:=s;
      readln(f,s);
      b:=ord(t);
      a:=ord(s);
      if (((a<123)and(a>96))or((a<91)and(a>64)))and((b<65)or(b>122)or((b>90)and(b<97))) then nr:=nr+1;
      if ((a>64)and(a<91))or((a>96)and(a<123)) then na:=na+1;
end;
x:=na div nr;
write(g,x);
close(f);close(g);
end.