View Code of Problem 71

#include <stdio.h>
using namespace std;
int main(){
	int N;
	scanf("%d", &N );
	double divided = 2;
	double divide = 1;
	double sum = 0;
	while( N-- ){
		sum += divided/divide;
		int temp = divided;
		divided = divided + divide;
		divide = temp; 
	}
	printf("%.2lf", sum );
	return 0;
	
}