If all bees were to die how long would humans have to live?

If bees died out, humans would not necessarily follow, but we would lose a lot of food plants and flowers that are currently pollinated by bees, so our diet would become a lot more monotonous, and there would probably be hunger. Thankfully, a proportion of our current diet comes from wind pollinated plants, for example, all plants derived from grasses such as wheat, barley, oats, maize and rice.