CodeForces Round #498 Div.3 A. Adjacent Replacements
http://codeforces.com/contest/1006/problem/A
Mishka got an integer array aa of length nn as a birthday present (what a surprise!).
Mishka doesn't like this present and wants to change it somehow. He has invented an algorithm and called it "Mishka's Adjacent Replacements Algorithm". This algorithm can be represented as a sequence of steps:
- Replace each occurrence of 11 in the array aa with 22;
- Replace each occurrence of 22 in the array aa with 11;
- Replace each occurrence of 33 in the array aa with 44;
- Replace each occurrence of