int maxA,maxR;
int A=0,R=1;

process contenitore {
	port int inizio_vers[2];
	port signal fine_vers;
	port signal inizio_estr;
	port signal fine_estr;
	process v, e;
	signal s;
	int qA,qR;
	int va = 0;
	do
		qA+1<maxA; v=receive from inizio_vers[A] ->
			qA++;
			va++;
			send(s) to v.ok;
		qR+1<maxR; v=receive from inizio_vers[R] ->
			qR++;
			va++;
			send(s) to v.ok;
		receive(s) from fine_vers ->
			va --;
		va==0 && qA==2*qR && qA+qR>=C; e=receive(s) from inizio_estr ->
			send(s) to e.ok;
			receive(s) from fine_estr
			qA = qA - 2/3*C;			
			qR = qR - 1/3*C;
	od
}

process versatore(X) {
	signal s;
	port ok;
	while(true){
		send(X) to contenitore.inizio_vers[X];
		receive(s) from ok;
		<versa>
		send(s) to contenitore.fine_vers;
	}
}

process estrattore() {
	signal s;
	port ok;
	while(true) {
		send(s) to contenitore.inizio_estr;
		receive(s) from ok;
		<estrai>
		send(s) to contenitore.fine_estr;
	}
}