int dig1=3;
int dig2=4;
int dig3=5;
int dig4=6;

void setup() {
  // put your setup code here, to run once:
pinMode(dig4, OUTPUT);
pinMode(dig3, OUTPUT);
pinMode(dig2, OUTPUT);
pinMode(dig1, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:

// 0 0000;
digitalWrite(dig4, LOW);
digitalWrite(dig3, LOW);
digitalWrite(dig2, LOW);
digitalWrite(dig1,LOW);
delay(1000);

// 1 0001;
digitalWrite(dig4, LOW);
digitalWrite(dig3, LOW);
digitalWrite(dig2, LOW);
digitalWrite(dig1,HIGH);
delay(1000);

// 2 0010;
digitalWrite(dig4, LOW);
digitalWrite(dig3, LOW);
digitalWrite(dig2, HIGH);
digitalWrite(dig1,LOW);
delay(1000);

// 3 0011;
digitalWrite(dig4, LOW);
digitalWrite(dig3, LOW);
digitalWrite(dig2, HIGH);
digitalWrite(dig1,HIGH);
delay(1000);


// 4 0100;
digitalWrite(dig4, LOW);
digitalWrite(dig3, HIGH);
digitalWrite(dig2, LOW);
digitalWrite(dig1,LOW);
delay(1000);


// 5 0101;
digitalWrite(dig4, LOW);
digitalWrite(dig3, HIGH);
digitalWrite(dig2, LOW);
digitalWrite(dig1,HIGH);
delay(1000);


// 6 0110;
digitalWrite(dig4, LOW);
digitalWrite(dig3, HIGH);
digitalWrite(dig2, HIGH);
digitalWrite(dig1,LOW);
delay(1000);


// 7 0111;
digitalWrite(dig4, LOW);
digitalWrite(dig3, HIGH);
digitalWrite(dig2, HIGH);
digitalWrite(dig1,HIGH);
delay(1000);


// 8 1000;
digitalWrite(dig4, HIGH);
digitalWrite(dig3, LOW);
digitalWrite(dig2, LOW);
digitalWrite(dig1,LOW);
delay(1000);


// 9 1001;
digitalWrite(dig4, HIGH);
digitalWrite(dig3, LOW);
digitalWrite(dig2, LOW);
digitalWrite(dig1,HIGH);
delay(1000);


// 10 1010;
digitalWrite(dig4, HIGH);
digitalWrite(dig3, LOW);
digitalWrite(dig2, HIGH);
digitalWrite(dig1,LOW);
delay(1000);


// 11 1011;
digitalWrite(dig4, HIGH);
digitalWrite(dig3, LOW);
digitalWrite(dig2, HIGH);
digitalWrite(dig1,HIGH);
delay(1000);


// 12 1100;
digitalWrite(dig4, HIGH);
digitalWrite(dig3, HIGH);
digitalWrite(dig2, LOW);
digitalWrite(dig1,LOW);
delay(1000);


// 13 1101;
digitalWrite(dig4, HIGH);
digitalWrite(dig3, HIGH);
digitalWrite(dig2, LOW);
digitalWrite(dig1,HIGH);
delay(1000);


// 14 1110;
digitalWrite(dig4, HIGH);
digitalWrite(dig3, HIGH);
digitalWrite(dig2, HIGH);
digitalWrite(dig1,LOW);
delay(1000);


// 15 1111;
digitalWrite(dig4, HIGH);
digitalWrite(dig3, HIGH);
digitalWrite(dig2, HIGH);
digitalWrite(dig1,HIGH);
delay(1000);



}