import java.math.BigInteger;

class Problem25

{

public static void main(String[] args)

{

long begin = System.currentTimeMillis();

BigInteger a = BigInteger.valueOf(1);

BigInteger b = BigInteger.valueOf(2);

BigInteger c = BigInteger.valueOf(0);

BigInteger MAX = new BigInteger("1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000");

int i = 3;

for (i = 3; b.compareTo(MAX) < 0; i++)

{

c = a.add(b);

a = b;

b = c;

}

System.out.println("index is : " + i);

long end = System.currentTimeMillis();

System.out.println(end - begin + "ms");

}

}