#include <stdio.h>
#include <stdlib.h>
char *P = 0;
int Pr(int n) {
  P = (char*)malloc(sizeof(char)*(n+1));
  int i;
  int j;
  for (i=0; i<=n; i++) P[i] = 1;
  P[0] = 0;
  P[1] = 0;
  for (i=2; i<=n; i++) {
    if (P[i] == 1) {
      for (j=i*2; j<=n; j+=i) {
        P[j] = 0;
      }
    }
  }
}
int main() {
  int N,L;
  scanf("%d %d",&N,&L);
  int i;
  long long int M = 0;
  if (2 <= L/(N-1)) {
    M += (L - 2*(N-1) + 1);
  }
  Pr(L/(N-1));
  for (i=3; i<=L/(N-1); i+=2) {
    if (P[i] == 1) {
      M += (L - i*(N-1) + 1);
    }
  }
  printf("%lld\n",M);
  return 0;
}