N = input()
A = map(int, raw_input().split())
A.sort()
ans = 1 << 50
for i in range(1, len(A)):
    if (A[i] == A[i - 1]):
        continue
    ans = min(ans,  abs(A[i] - A[i - 1]))
if (ans == 1 << 50):
    print 0
else:
    print ans