import math
t=[]
while True:
    try: t.extend(input().split())
    except EOFError:break
g=[int(x) for x in t];i=0
while i<len(g):
    n,m=g[i],g[i+1];i+=2;p=[]
    for _ in range(m): p.append((g[i],g[i+1]));i+=2
    md=float('inf')
    for i in range(m):
        for j in range(i+1,m):
            d=math.sqrt((p[i][0]-p[j][0])**2+(p[i][1]-p[j][1])**2)
            if d<md: md=d
    print(f"{md:.4f}")