import Foundation

func readInts() -> [Int] {
    return readLine()!.split(separator: " ").map { Int($0)! }
}

func readStr() -> [String] {
  let str:String = readLine()!
  let arr:[String] = str.components(separatedBy: " ")
  return arr
}

let nb=readInts()
let n=nb[0]
let strs=readStr()
let S=strs[0]
let T=strs[1]

var ans:String=""

for i in 0..<n{
  let c1=S[S.index(S.startIndex,offsetBy:i)]
  let c2=T[T.index(T.startIndex,offsetBy:i)]
  ans+=String(c1)+String(c2)
}

print(ans)