F. Railway Renovation (rail)
time limit per test
3 seconds
memory limit per test
512 megabytes
input
standard input
output
standard output
Examples
Input
4 4
1 2
2 3
3 4
4 1
Output
RBRB
Input
4 4
1 2
2 3
3 1
1 4
Output
RBRB
Input
4 5
1 2
1 3
1 4
2 3
3 4
Output
RRBBR