Program string_15;
uses crt;
var
t: string;
i: integer;
ot: boolean;
begin
clrscr;
writeln('введите текст:');
readln(t);
for i := 1 to length(t) do
if t[i] = 's' then
ot := true;
if ot = true then
write('да')
else
write('нет');
readln;
end.