View Code of Problem 71

#include<stdio.h>
#include<math.h>
int main()
{
  int c,n;
  scanf("%d",&n);
  int a=2,b=1;
  double sum=0.0;
  for(int i=1;i<=n;i++)
  {
  sum+=(double)a/b;
    c=a+b;
    b=a;
    a=c;
  }
printf("%.2f",sum);
  return 0;
  
}