Add problem description at BigMod

UVa/BigMod.java

@@ -1,4 +1,34 @@
+/**
+ * Calculate
+ * R := B
+ * P mod M
+ * for large values of B, P, and M using an efficient algorithm. (That’s right, this problem has a time
+ * dependency !!!.)
+ * Input
+ * The input will contain several test cases, each of them as described below. Consecutive test cases are
+ * separated by a single blank line.
+ * Three integer values (in the order B, P, M) will be read one number per line. B and P are integers
+ * in the range 0 to 2147483647 inclusive. M is an integer in the range 1 to 46340 inclusive.
+ * Output
+ * For each test, the result of the computation. A single integer on a line by itself.
+ * Sample Input
+ * 3
+ * 18132
+ * 17
+ * 17
+ * 1765
+ * 3
+ * 2374859
+ * 3029382
+ * 36123
+ * Sample Output
+ * 13
+ * 2
+ * 13195
+ */
+
 //https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=727&page=show_problem&problem=310
+
 import static java.lang.Integer.parseInt;
 import static java.lang.System.exit;