You are given an array of strings equations that represent relationships between variables where each string equations[i] is of length 4 and takes one of two different forms: x==y or x!=y. Here x and y represents lowercase letters.
Input Format
First line contains an integer denoting the number of equation Each of next n line contains an equation of form "x==y" or "x!=y"
Output Format
print true if all equations can be satisfied else print false.
Constraints
1 <= equations.length <= 100000 equations[i].length == 4
Example
Input
2 b==c c!=b
Output
false