function Main (input) {
  input = input.split("\n").map(inp1 => parseInt(inp1, 10));
  if (input.every(inp => inp != 1)) console.log(1);
  if (input.every(inp => inp != 2)) console.log(2);
  if (input.every(inp => inp != 3)) console.log(3);
}

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