var f,g:text;
    s:string;
    i,nr,l:integer;
begin
assign(f,'text.in');reset(f);
assign(g,'text.out');rewrite(g);
while not(eof(f)) do
                 readln(f,s);
for i:=1 to length(s) do      
    if (s[i]=' ') and (s[i+1] in ['a'..'z','A'..'Z']) or (s[i]='-') and (s[i+1] in ['a'..'z','A'..'Z']) then inc(nr)
    else
        if s[i] in ['a'..'z','A'..'Z'] then inc(l);
writeln(g,trunc(l/nr));
close(f);close(g);
end.