const n = require("fs").readFileSync(0, "utf8").toString().split("\n").map(Number);
let arr = Array.from({length:30}, (_,i) => i+1);
for(let i=0; i<28; i++) arr[n[i]-1] = 0;
for(let j=0; j<30; j++) if(arr[j]!=0) console.log(arr[j]);