Simple and delicious iced coffee recipe

My roomate Eliana told me how to make this-she learned from another missionary lady.  It's so good!

1 cup instant coffee
2 cups of sugar
3 cups of hot water
1 small bottle of vanilla (I think about 1/8-1/4 cup)
Mix together and store in fridge. It seems that it will last a few weeks (My roommate left it over two weeks for winter break and it was still delicious!)
Then you add milk and ice to it and enjoy iced coffee (Or you can add hot milk and have hot coffee!). About 1/4 to 1/3 cup of coffee concentrate mix and the rest milk and ice should be just about right.
Provecho!