Consider the following program. The main program is an infinite loop. The CPU enters a low power mode where the CPU, MCLK$,$ SMCLK$,$ and the DCO oscillator are all turned off, ACLK stays on$.$ The WDT interrupt service routine should wake the CPU up every $1000$ ms $(1$s$).$ The CPU then pulses an LED connected at the P$1\mathrm{.}0($turns it on$,$ keeps it on for some time, and then turns it off$)$ and then enters the LPM mode again. Write a simple program at the beginning of the main routine as well as what needs to be done in the WDT interrupt service routine. Assume that a watch crystal of $32768$ Hz is connected to LFXT$1.$ Could you estimate how long the LED will be on$?(25$ points$)$