void stop()}
 digitalWrite(ENA'LOW)
 digitalWrite(ENB,low)
 serial.println("stop!");
 }
 void setup(){
 serial.begin(9600);
 pinMode(LT_R,INPUT);
 pinMode(LT_M,INPUT);
 void loop(){
 if(LT_M{
 forward();
 }
 else if(LT_R){
 right();
 while(LT_R);
 }
 else if(LT_L){
 left();
 while(LT_L);
 }
 }