private static String getMinNumber(long element, long denominator){
		
		BigInteger a = new BigInteger(String.valueOf(element));
		
		BigInteger c = new BigInteger(String.valueOf(denominator));
		BigInteger result = a.multiply(b).mod(c);
		if (result.intValue() != 0){
			return "impossible";
		} else {
			long elfRate = a.multiply(b).divide(c).longValue();
			
			for (int i = 0; i <= 40; i++){
				if (pow2List.get(i) == elfRate){
					return String.valueOf(40 - i);
				}
				
				if (pow2List.get(i) > elfRate && pow2List.get(i - 1) < elfRate){
					return String.valueOf(40 - i + 1);
				}
			}
			
			return "??";
		}
	}