#include <stdio.h>
FILE *fi;
FILE *fo;
long long n, p, i=0, k=0;
int prim (long long x, long long y) {
long long min, i;
if (x<y) min=x;
else min=y;
for (i=2; i<=min; i++) {
if (x%i==0 && y%i==0) return 0;
}
return 1;
}
int main (void) {
	fi=fopen("frac.in", "rt");
	fo=fopen("frac.out", "wt");
	fscanf (fi, "%lld %lld", &n, &p);
	while (k!=p) {
	i++;
	if (prim(i, n)==1) k++;
	} 
	fprintf(fo, "%lld", i);
	fcloseall();
	return 0;
}