Period and Frequency of Sound Waves as Shown on the Screen

Problem Statement

To investigate the properties of sound in a laboratory, a device (an electromagnetic tuning fork) that maintains a constant electrical oscillation was used to generate a sound of a specific pitch. The frequency $f$f of this device is expressed in $\mathrm{Hz}$Hz and represents the number of times the medium vibrates per second.

Now, the sound waves emitted by this device were captured by a microphone and displayed on a computer screen. The time from the highest point of a wave (a crest) to the next crest is called the period $T$T of the sound wave. The unit for the period $T$T is the second $\mathrm{s}$s.

The following relationship holds between the frequency $f$f and the period $T$T.

$$f = \frac{1}{T}$$f=T1​

When the period $T$T of this device was measured, its value was expressed as $T = \frac{1}{t}$T=t1​, where $t$t is a variable. Find the value of the frequency $f$f in this case, and determine the natural number that satisfies the following input format.

Constraints

• $t = 400\text{ }\mathrm{s^{-1}}$t=400 s−1

Input Format

Let $A$A be the numerical value of the frequency $f$f. Enter the value of $A$A as a natural number.