func encryption(s: String) -> String {
    let strLength = s.count
    let squareRootOfLength = Double(strLength).squareRoot()
    let columnCount = Int(ceil(squareRootOfLength))
    var grid = [[Character]]()
    var encodedString = ""
    
    var columnNumber = 0
    var row = [Character]()
    
    //Creating grid
    for charactor in s {
        if columnNumber < columnCount {
            row.append(charactor)
            columnNumber += 1
        }else{
            grid.append(row)
            row.removeAll()
            row.append(charactor)
            columnNumber = 1
        }
    }
    grid.append(row)
    
    //Creating encoded string by reading the grid
    for columnNumber in 0...columnCount - 1 {
        for row in grid {
            guard columnNumber < row.count else {
                break
            }
            encodedString += String(row[columnNumber])
        }
        encodedString  += columnNumber < columnCount ? " " : ""
    }
    
    return encodedString
}