Touchless elevator using arduino

int a,b,x,d;

void setup() {
  
  // put your setup code here, to run once:
pinMode(6,OUTPUT);
pinMode(9,OUTPUT);
pinMode(2,INPUT);
pinMode(3,INPUT);
pinMode(4,INPUT);
pinMode(1,OUTPUT);
pinMode(5,OUTPUT);
pinMode(7,OUTPUT);
pinMode(8,OUTPUT);
pinMode(10,OUTPUT);
pinMode(11,OUTPUT);
pinMode(12,OUTPUT);
pinMode(13,OUTPUT);

Serial.begin(9600);
}
int c=1;
void loop() {
  // put your main code here, to run repeatedly:

a=digitalRead(2);
b=digitalRead(3);
d=digitalRead(4);
if (a==1)
{
  x=3;
  switch (c)
  {
    case 1:{
              digitalWrite(6,HIGH);
              digitalWrite(9,LOW);
              delay(12250);
              digitalWrite(6,LOW);    
              break;
          }
    case 2:{
              digitalWrite(6,HIGH);
              digitalWrite(9,LOW);
              delay(6000);
              digitalWrite(6,LOW);    
              break;
          }
   
     case 3:{
              Serial.print("you have reached the floor!\n");     
              Serial.println();
              break;            
     }
  }
  digitalWrite(5,LOW);
  digitalWrite(7,LOW);
  digitalWrite(8,LOW);
  digitalWrite(10,LOW);
  digitalWrite(11,HIGH);
  digitalWrite(12,LOW);
  digitalWrite(13,HIGH);
  
  }

if (b==1)
{
  x=2;
  switch (c)
  {
    case 1:{
              digitalWrite(6,HIGH);
              digitalWrite(9,LOW);
              delay(6000);
              digitalWrite(6,LOW);    
              break;
          }
    case 2:{
      Serial.print("you have reached the floor!\n");     
              Serial.println(); 
             break;
          } 
     case 3:{
               digitalWrite(6,LOW);
              digitalWrite(9,HIGH);
              delay(6000);
              digitalWrite(9,LOW);    
              break;           
     }
  }
    digitalWrite(5,LOW);
  digitalWrite(7,LOW);
  digitalWrite(8,HIGH);
  digitalWrite(10,LOW);
  digitalWrite(11,LOW);
  digitalWrite(12,LOW);
digitalWrite(13,HIGH);

}
 

if (d==1)
{
  x=1;
  switch (c)
  {
    
    case 1:{
              Serial.print("you have reached the floor!\n");     
              Serial.println(); 
             break;
              
          }
    case 2:{
              digitalWrite(6,LOW);
              digitalWrite(9,HIGH);
              delay(6000);
              digitalWrite(9,LOW);    
              break;
          } 
     case 3:{
               digitalWrite(6,LOW);
              digitalWrite(9,HIGH);
              delay(11000);
              digitalWrite(9,LOW);    
              break;           
     }
  }
      digitalWrite(5,HIGH);
  digitalWrite(7,LOW);
  digitalWrite(8,LOW);
  digitalWrite(10,HIGH);
  digitalWrite(11,HIGH);
  digitalWrite(12,HIGH);
  digitalWrite(13,HIGH);
  digitalWrite(1,HIGH);
}

  
}