function Main(input) {
  const N = parseInt(input.trim())
  let result = (N % 2 === 1) ? "7" : "4"
  for (let i = 0; i < ~~(N / 2); i++) {
    result += "4"
  }
  console.log(result)
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"))