# Satisfiability Of Equality Equation

easy

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.

## Constraints

1 <= equations.length <= 100000 equations[i].length == 4

## Format

### Input

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

print true if all equations can be satisfied else print false.

## Example

Sample Input

2
b==c
c!=b

### Sample Output

false