import sys
read=sys.stdin.buffer.read
readline=sys.stdin.buffer.readline
readlines=sys.stdin.buffer.readlines
n=int(readline())
xy=list(map(int, read().split()))
x=xy[::2]
y=xy[1::2]
INF=3*10**18
d=[INF]*n
d[0]=0
dq=[INF]*n
dq[0]=0
for _ in range(n):
    i=dq.index(min(dq))
    d1=dq[i]
    if i==n-1 or d1==INF:
        break
    x1, y1=x[i], y[i]
    dq[i]=INF
    for j, (x2, y2) in enumerate(zip(x, y)):
        d2=max(d1, (x1-x2)*(x1-x2)+(y1-y2)*(y1-y2))
        if d[j]>d2:
            d[j]=d2
            if dq[j]>d2:
                dq[j]=d2
mn=d[n-1]
l, r=0, 2*10**8
while r-l>1:
    m=(l+r)//2
    if 100*m*m>=mn:
        r=m
    else:
        l=m
print(10*r)