Keep Only the Highest Set Bit

#include <stdio.h>
#include <stdint.h>
#include <math.h>
// Complete the function
uint16_t highest_set_bit(uint16_t reg) {
    if(reg==0){
        return 0;
    }
    int c=0,a=2,b;
    for (int i=0;i < 16;i++){
        if(reg & (1<<i)){
            c = i;            
        }    

    }
    b = pow(a , c);
    reg=reg^b;


    return b;

    // Your logic here
}

int main() {
    uint16_t reg;
    scanf("%hu", &reg);

    uint16_t result = highest_set_bit(reg);
    printf("%hu", result);
    return 0;
}