Подчеркните все простые числа среди первых 30 натуральных чисел

1, 2, 3,4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30