View Code of Problem 71

#include <stdio.h>
int main()
{   
    float a, b, c, sum = 0;
    int i;
    a = 2.0;
	b = 1.0;
	int n;
	scanf("%d", &n);
    for(i = 0; i < n; i++)
    {
        sum += a / b;
        c = b;
        b = a;
        a += c;  
    }
    printf("%.2f\n", sum);
    return 0;
}