const int latchPin = 5;
const int clockPin = 6;
const int dataPin = 4; 
int keyPin = 13;
int data[16] = {254, 176, 237, 249, 179, 219, 223, 240, 255, 243, 247, 159, 206, 189, 199};
void Displ(int num);

void setup () {
  pinMode(latchPin,OUTPUT);
  pinMode(clockPin,OUTPUT);
  pinMode(dataPin,OUTPUT);
  Displ(0);
 }

int x = -1;  
int button_old = 1;
void loop() {
   if((digitalRead(keyPin) == LOW)&&(button_old == 1)) {
      x = x + 1;
    }
   Displ(0);
   Displ(x);
   if (x > 15) {x = 0;}
 
   button_old = digitalRead(keyPin);
   delay(20);
 }

void Displ(int num) {
    digitalWrite(latchPin,LOW);
    shiftOut(dataPin,clockPin,LSBFIRST,data[num]);
    digitalWrite(latchPin,HIGH);
 }