#include <stdio.h>

int power(double base, int expo){
	if(expo <= 0) return 1;
	double result;
	if((expo%2) == 0){
		result = power(base,expo>>1)*power(base,expo>>1);
	}else{
		result = power(base,(expo-1)>>1)*power(base,(expo-1)>>1)*base;
	}
	return result;
}


int main(){
	double result = power(2,4);
	printf("%f\n",result);
	return 0;
}