Capital#1724
In the thrice-ninth kingdom, within the thrice-ninth state, every pair of cities is connected by a one-way road. The location of the king's residence is a secret, but it is known that the capital city can be reached from any other city by traveling through at most one intermediate city.
Your task is to write a program that determines the possible location of the capital based on the information about the country's roads.
The first line of the input contains a single integer (1 \le N \le 100), representing the number of cities.
The following (N-1) lines each contain only the symbols "+" (plus) and "-" (minus). The length of the -th line is i-1. The -th symbol in the -th line indicates the direction of the road: "+" means the road goes from city to city ; "-" means the road goes from city to city .
On the first line, output the number of candidate cities for the capital's location. On the second line, output the numbers of these candidate cities in ascending order, separated by spaces.
Example 1