import random
gen=[]
result=[]   ##[차,[b],[b+1]]
t=0
u=0
v=0
while v<8:
    r=random.randint(1,20)
    gen.append(r)
    v+=1

gen.sort()
comp=gen[1]-gen[0]

for a in range(1, len(gen)):
    result.append([gen[a]-gen[a-1],gen[a-1],gen[a]])

print(result)
print("-------------------------------------------------")

for b in range(0, len(result)-1):
    if comp>result[b][0]:
        comp=result[b][0]

print(comp)

for c in range(0, len(result)-1):
    if result[c][0] == comp:
        print([result[c][1], result[c][2]])