View Code of Problem 71

#include<stdio.h>
int main(){
	int n;
	scanf("%d",&n);
	float up=2;
	float down=1; 
	float sum=0;
	float t;
	for(int i=1;i<=n;i++){
		sum=sum+up/down;
		t=up;
		up=up+down;
		down=t;
		
	}
	printf("%.2f",sum);
	
	return 0;
}