Problem:
Score : 100 points

Problem Statement

Given are two strings S and T consisting of lowercase English letters. Concatenate T and S in this order, without space in between, and print the resulting string.

Constraints

S and T are strings consisting of lowercase English letters.

The lengths of S and T are between 1 and 100 (inclusive).

Input

Input is given from Standard Input in the following format:

S T

Output

Print the resulting string.

Sample Input 1

oder atc

Sample Output 1

atcoder

When S = oder and T = atc, concatenating T and S in this order results in atcoder.

Sample Input 2

humu humu

Sample Output 2

humuhumu

Solution in Go (1.6) (judge verdict: Runtime Error)

package main

import (
  "fmt"
  "regexp"
  "os"
)

func main() {
    
    if(len(os.Args) != 3) {
        panic("argument error:")
    }
    var firstWord = os.Args[0]
    var secondWord = os.Args[1]
    
    var firstWordLength = len(firstWord)
    var secondWordLength = len(secondWord)

    var regexpSmallAlphabet = regexp.MustCompile(`^[a-z]*$`)

//    fmt.Println("firstWord:", firstWordLength, "&", regexpSmallAlphabet.Match([]byte(firstWord)))
//    fmt.Println("secondWord:", secondWordLength, "&", regexpSmallAlphabet.Match([]byte(secondWord)))

    // length 1 - 100 and small a - z
    if(firstWordLength < 1 || 100 < firstWordLength) {
        panic("allow length 1 to 100")
    }
    if(secondWordLength < 1 || 100 < secondWordLength) {
        panic("allow length 1 to 100")
    }
    if(!regexpSmallAlphabet.Match([]byte(firstWord)) || !regexpSmallAlphabet.Match([]byte(secondWord))) {
        panic("allow char a to z")
    }

    fmt.Sprintf("%s%s", firstWord, secondWord)
}