#define led1 13
#define led2 12
#define led3 11
#define led4 10
#define interruptPin1 3
#define interruptPin2 2
volatile int num = 0;

void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  pinMode(interruptPin1, INPUT_PULLUP);
   pinMode(interruptPin2, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(interruptPin1),increment,FALLING);
  attachInterrupt(digitalPinToInterrupt(interruptPin2),decrement,FALLING);
  Serial.begin(9600);
  
}

void loop() {
  Serial.println(num);
  digitalWrite(led1,!digitalRead(led1));
  delay(250);


}
void increment() {
  (num<99)? num++:num=0;
}

void decrement(){
  (num>0)? num--:num=99;
}