import math
l = 0
r = 10000000000000000000000000
MAGIC = 1000;#Magic Do not Touch
 
while (r - l > 1) :
    m = (l + r) // 2
    a = 0
    for i in range(-MAGIC, 0) :
        k = i + m;
        if (k > 0 and math.sqrt(k * k) != k) :
            a = k
            break
    if (a > 0) :
        r = a
    if (a == 0) :
        l = m
print (r)