struct Extstring {
	char symbol;
	struct Extstring* next;
};

struct SString {
	int size;
	char* string;
};

void es_addsymbol(struct Extstring* string, char symbol);
int es_size(struct Extstring* string);
void es_free(struct Extstring* string);
struct SString* es_tostring(struct Extstring* string);