문제<\/h2>
Kenny has a microwave in his kitchen. The microwave has a pretty weird one-button timer interface. <\/p>
When you have put some food into the microwave and want it to start heating, you should press the button one or multiple times. When you press the button for the first time, the timer is set for $1<\/mn><\/mrow>1<\/math><\/span><\/span> 1<\/span><\/span><\/span><\/span> minute. If you immediately press the button again, 2<\/mn><\/mrow>2<\/math><\/span><\/span> 2<\/span><\/span><\/span><\/span> minutes are added to the timer, for a total of 3<\/mn><\/mrow>3<\/math><\/span><\/span> 3<\/span><\/span><\/span><\/span> minutes. If you immediately press the button yet again, 4<\/mn><\/mrow>4<\/math><\/span><\/span> 4<\/span><\/span><\/span><\/span> more minutes are added to the timer, and so on. If you press the button for the k<\/mi><\/mrow>k<\/math><\/span><\/span> k<\/span><\/span><\/span><\/span>-th time without a pause, it adds 2<\/mn>k<\/mi><\/msup><\/mrow>2^k<\/math><\/span>$

Kitchen Timer