def minimumDistances(arr):
    dct={}
    for i in range(len(a)):
        if arr[i] in dct:
            dct[arr[i]].append(i)
        else:
            dct[arr[i]]=[i]
    ans=[]
    #print(dct)
    for lis in dct:
        if len(dct[lis])>1:
            ans.append(abs(dct[lis][0]-dct[lis][1]))
    #print(ans)
    if ans == []:
        return '-1'
    return min(ans)