n=int(input()) a=input().split() a=[int(x)for x in a] b=10**10 c=0;d=0 for i in range(1,n): for j in range(i): # print(i,j) if abs(a[i]-a[j])<b: b=abs(a[i]-a[j]) c=i d=j # print() print(b) # print(c+1,d+1)