const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;
void async function () {
// Write your code here
while(line = await readline()){
let num = Number(line);
let str=''
if(num===1){
str=num
}else{
let arr=[]
arr[0]=num**2-num+1
for(let i=1;i<num;i++){
arr[i]=arr[i-1]+2
}
str=arr.join('+')
}
console.log(str);
}
}()