1200 calories a day to lose weight?

If I eat 1200 calories a day for 5 whole weeks, but I do not run on the treadmill or do any other type of exercise (besides my daily walking) will I lose weight? I want to look good for swimsuit season and I have a little stomach chub, it's not a lot but I would like to lose it in time for summer. Any suggestions/helpful comments? Thanks so much!