rem: bclass(c)
add: bclass(int c)
context: bclass(c){	switch (c) {	case '{': bracecnt++; break;	case '}': bracecnt--; break;	case '[': brackcnt++; break;	case ']': brackcnt--; break;	case '(': parencnt++; break;	case ')': parencnt--; break;	}}