program z1;
var s:string;
i,L,maxL:integer;
begin
readln(s);
L:=0;
maxL:=0;
for i:=0 to length (s) do
if s[i] in ['A','B','E','F'] then
begin
L:=L+1;
if L>maxL then
maxL:=L;
end
else
L:=0;
writeln(maxL);
end.
RError.com
