uses crt;
var d:longint; s,c:string;
begin
clrscr;
repeat
write('Nhap ki tu: ');readln(c);
until c=upcase(c);
repeat
write('Nhap xau: ');readln(s);
until s=upcase(s);
while pos(c,s)<>0 do
begin
inc(d);
delete(s,pos(c,s),1);
end;
writeln('Co ',d,' ki tu ',c,' trong xau');
readln;
end.