Program string_19;
uses crt;
var
a: string;
i, l, k: longint;
label m;
begin
clrscr;
write('введите предложение: ');
readln(a);
l := length(a);
m:
for i := 1 to l do
if (a[i] = 'ч') and (a[i + 1] = 'т') and (a[i + 2] = 'о') then
begin
l := l - 3;
delete(a, i, 3);
inc(k);
goto m;
end;
write('кол-во слов "что": ', k);
readln;
end.