#include <bits/stdc++.h>
using namespace std;

int main(){
    int N;
    long S;
    scanf("%d %ld",&N,&S);
    long x = 1;
    while(1){
        if(x*(x-1)/2 < S && S <= x*(x+1)/2){
            break;
        }
        x++;
    }
    if(S == x*(x+1)/2){
        printf("%d\n",x);
    } else {
        printf("%d\n",x-1);
    }
    for(long i=1;i<=x;i++){
        if(i != x*(x+1)/2 - S){
            printf("%ld ",i);
        }
    }
}