Japanese Potato Salad (美味しいポテトサラダの作り方)

Ingredients:

300g (10.6oz.) potato
50g (1.8oz.) carrot
50g (1.8oz.) onion
50g (1.8oz.) cucumber
2 cooked sliced ham
1/2 cup whole kernel corn (canned)
1/2 tbsp. vinegar (rice or cereal)
4 tbsp. mayonnaise
salt and pepper