package main import ( "fmt" "strings" ) func main() { var n int fmt.Scan(&n) fmt.Println(matchNum(n, "")) } func matchNum(leftMatch int, matchNumMemo string) string { if leftMatch < 2 { return matchNumMemo } if leftMatch == 2 { return strings.Join([]string{matchNumMemo, "1"}, "") } if leftMatch%2 == 1 { return matchNum(leftMatch-3, strings.Join([]string{matchNumMemo, "7"}, "")) } return matchNum(leftMatch-2, strings.Join([]string{matchNumMemo, "1"}, "")) }