#include<stdio.h>
#define IN_FILE  "1-sir.in"
#define OUT_FILE "1-sir.out"
FILE *f1,*f2;
int n,s;
int main()
{
 f1=fopen(IN_FILE,"r");
 f2=fopen(OUT_FILE,"w");
  fscanf(f1,"%d",&n);
  fscanf(f1,"%d",&s);
//  if(s>(n*(n-1)/2) || s<(-1*n*(n-1)/2))
    fprintf(f2,"0");
 fclose(f1);
 fclose(f2);
 return 0;
}