#include<bits/stdc++.h>
using namespace std;
int n,b=3,a;
main(){
cin>>n;
while(n--){
cin>>a;
if(a==b)return cout<<"NO",0;
b=6-a-b;
}
cout<<"YES";
}
e-maze-in | Bricks Game |
Char Sum | Two Strings |
Anagrams | Prime Number |
Lexical Sorting Reloaded | 1514A - Perfectly Imperfect Array |
580A- Kefa and First Steps | 1472B- Fair Division |
996A - Hit the Lottery | MSNSADM1 Football |
MATCHES Playing with Matches | HRDSEQ Hard Sequence |
DRCHEF Doctor Chef | 559. Maximum Depth of N-ary Tree |
821. Shortest Distance to a Character | 1441. Build an Array With Stack Operations |
1356. Sort Integers by The Number of 1 Bits | 922. Sort Array By Parity II |
344. Reverse String | 1047. Remove All Adjacent Duplicates In String |
977. Squares of a Sorted Array | 852. Peak Index in a Mountain Array |
461. Hamming Distance | 1748. Sum of Unique Elements |
897. Increasing Order Search Tree | 905. Sort Array By Parity |
1351. Count Negative Numbers in a Sorted Matrix | 617. Merge Two Binary Trees |