C bit 처리

#include <stdio.h>

int bits(){
printf("\n");

int numberHowBig = 0;

printf("How Many Bits? ");
scanf(" %d", &numberHowBig);
printf("\n\n");

// 0 : Print what is given
// 1 : print what is given
// 2 : 1 + 2 = 3 11
// 4 : 7 + 8 = 15 1111

int myIncrementor = 1, myMultiplier = 1, finalValue = 1;

while(myIncrementor < numberHowBig){
myMultiplier *= 2;
finalValue = finalValue + myMultiplier;
myIncrementor++;
}

if((numberHowBig == 0) || (numberHowBig == 1)){
printf("Top Value: %d\n\n", numberHowBig);
} else {
printf("Top Value: %d\n\n", finalValue);
}
}

void main(void)
{
bits(); // input 31 -> How Many Bits? 31
        // // input 32 -> Top Value: -1

}