Another solution for easy understanding, hope it helps. var gemCounter = 0 var switchCounter = 0 while gemCounter >= switchCounter {     moveForward()     if isBlocked && isBlockedLeft {         turnRight()     }     while isOnGem {         collectGem()         gemCounter += 1     }     while isOnClosedSwitch && switchCounter !=  gemCounter {         toggleSwitch()         switchCounter += 1         if switchCounter == gemCounter {                          switchCounter += 1         }              } }