function Main(input){
  	input = input.trim()
  	input = input.split("\n")
    input[0] = input[0].split("").map(Number)
  //console.log(input[0])
  input[0] = input[0].reverse()
    input[1] = input[1].split("").map(Number).reverse()
 
  //console.log(input)
  //console.log(input[0])
    len = Math.max(input[0].length,input[1].length)
  if(input[0].length<input[1].length){
      while(input[0].length!== input[1].length){
          input[0].push(0)
        //console.log("a")
      }
   }else{
      while(input[0].length!== input[1].length){
          input[1].push(0)
      }
   }
   //console.log(input,input[0].length<input[1].length)
    res = []
    for(a = 0;a<len;a++){
      if(input[0][a]+input[1][a] == 2){
         res.push(0)
         }else{
    	  res.push(input[0][a]+input[1][a])
         }
      //console.log(res)
    }
  res = res.reverse()
  res = res.join("")
  res = Number(res)
  console.log(res)
  
}


Main(require("fs").readFileSync("/dev/stdin", "utf8"));