Nguồn: http://codeforces.com
Petya loves football very much.
One day, as he was watching a football match, he was writing the players'
current positions on a piece of paper. To simplify the situation he depicted it
as a string consisting of zeroes and ones. A zero corresponds to players of one
team; a one corresponds to players of another team. If there are at least 7 players
of some team standing one after another, then the situation is considered
dangerous. For example, the situation 00100110111111101 is
dangerous and 11110111011101 is not. You are given the current situation.
Determine whether it is dangerous or not.
Input
The first input line contains a
non-empty string consisting of characters "0" and "1",
which represents players. The length of the string does not exceed 100 characters.
There's at least one player from each team present on the field.
Output
Print "YES" if the
situation is dangerous. Otherwise, print "NO".
Examples
input
001001
output
NO
input
1000000001
output
YES
Tóm tắt đề:
_
Có N cầu thủ được xếp thành 1 hàng ngang. N cầu thủ này thuộc về 2 đội khác
nhau.
_
Một sắp xếp được gọi là “dangerous” nếu như có ít nhất 7 cầu thủ ở đội này đứng
đằng sau một cầu thủ ở đội khác.
_
Cho một sắp xếp các chỗ đứng của cầu thủ, hỏi hàng sắp xếp này có “dangerous”
hay không?
Solution By ĐNK
