const int buttonA = 11; // main external press button A
const int buttonB = 12; // internal button B
const int buttonC = 13; // internal button C
const int IN1Pin = 5;
const int IN2Pin = 6;
bool running = 0;
bool flag3 = 0;

void setup() {
// put your setup code here, to run once:
pinMode (buttonA,INPUT_PULLUP);
 pinMode (buttonB,INPUT_PULLUP);
 pinMode (buttonC,INPUT_PULLUP);
  pinMode ( IN1Pin,OUTPUT);
  pinMode ( IN2Pin,OUTPUT);
  Serial.begin (9600); 
}

void loop() {
 // put your main code here, to run repeatedly:
 if ((digitalRead(buttonA) == LOW) and (digitalRead(buttonB) == HIGH) and (digitalRead(buttonC) == LOW)) //On a press
  { 
   digitalWrite(IN1Pin,LOW); 
   digitalWrite(IN2Pin,HIGH);
   Serial.println ("start");
  } 

 if ( (digitalRead(buttonA)== HIGH) and (digitalRead(buttonB) == LOW) and(digitalRead(buttonC)==HIGH) )// switch to go back
  {
   digitalWrite(IN1Pin,HIGH);
   digitalWrite(IN2Pin,LOW);
   Serial.println ("moving back");
  }


 if ( (digitalRead(buttonA)== HIGH) and (digitalRead(buttonB) ==HIGH) and(digitalRead(buttonC)==LOW) )
 {
   digitalWrite(IN1Pin, LOW);
   digitalWrite(IN2Pin, LOW);
   Serial.println ("stop");
  }
 
}