import sys
input = sys.stdin.readline

N,M=map(int,input().split())

if N==1:
    print("NaN")
    exit()

LIST=[0]*(10**7)
LIST[0]=1

now=0

for i in range(1,5*10**6+1):

    while True:
        if (now+1)*(now+1)<=N*i*i:
            now+=1
        else:
            break

    if now<10**7:
        LIST[now]=1
    else:
        break

count=0
for i in range(10**7):
    if LIST[i]==0:
        count+=1

    if count==M:
        print(i)
        break