Solution of URI 2161 :: Square Root of 10

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/**Bismillahir Rahmanir Rahim.**/

#include <stdio.h>
int main()
{
    double n, ans = 0.0;
    scanf("%lf", &n);
    while(n--)
    {
        ans+=6.0;
        ans = 1.0/ans;
    }
    ans += 3.0;
    printf("%.10lf\n", ans);
    return 0;
}