function Main(input) {
  let data = input.split("\n");
  // let data = input.split(" ");
  let A = data[0];
  let B = data[1];
  // let  = Number(data[0]);
  // let  = Number(data[1]);

  let arrayA = A.split('');
  let count = 0;

  for (i=0; i<arrayA.length; i++) {
    reg =  new RegExp(arrayA[i], "g");
    check = (B.match(reg) || [] ).length ;
    if (check===1) {
      count ++;
    } else {
      break;
    }
  }
  if (count === B.length){
    console.log('YES\n');
  } else {
    console.log('NO\n');
  }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));