View Compilation Error

0_0_5958220_5071\Main.java:10: cannot find symbol
symbol  : method valueOf(java.math.BigInteger)
location: class java.math.BigInteger
			BigInteger x=BigInteger.valueOf(cin.nextBigInteger());
			                       ^
0_0_5958220_5071\Main.java:11: cannot find symbol
symbol  : method valueOf(java.math.BigInteger)
location: class java.math.BigInteger
			BigInteger y=BigInteger.valueOf(cin.nextBigInteger());
			                       ^
2 errors