int baseLed = 2;
int numLed = 5;
int delayTime= 1000;
int bPinA=10;
int bPinB=11;

void setup() {
  // put your setup code here, to run once:
  for(int i=0; i<numLed; i++){
    pinMode(baseLed+i,OUTPUT);
    digitalWrite(baseLed+i,LOW);
  }
    pinMode(bPinA,INPUT);
    pinMode(bPinB,INPUT);
}

void cycle() {
  for(int i=0; i<numLed; i++){
    digitalWrite(baseLed+i,HIGH);
    delayTime = changeDelay ();
    delay(delayTime);
    digitalWrite(baseLed+i,LOW);
}
}

int changeDelay () { 
  if (digitalRead(bPinA)) {
  delayTime= delayTime + 100;
}
  if (digitalRead(bPinB)) {
  delayTime= delayTime - 100;
  }
  if (delayTime>2000) {
    delayTime=2000;
  }
  if (delayTime<100) { 
    delayTime=100;
  }
  return delayTime;
  }



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