a = [0,9,8,7,6,5,4,3,2,1]
r = 4
res = a.copy()
for i in range (len(a)-1, -1, -1):
res[i-r] = a[i]
# print(i)
# print(i-r)
# print(a[i])
# print("----")
# res.insert(i-r, a[i])
# print(res)
# print("======")
print(res)
YSA9IFswLDksOCw3LDYsNSw0LDMsMiwxXQpyID0gNApyZXMgPSBhLmNvcHkoKQpmb3IgaSBpbiByYW5nZSAobGVuKGEpLTEsIC0xLCAtMSk6CglyZXNbaS1yXSA9IGFbaV0KCSMgcHJpbnQoaSkKCSMgcHJpbnQoaS1yKQoJIyBwcmludChhW2ldKQoJIyBwcmludCgiLS0tLSIpCgkjIHJlcy5pbnNlcnQoaS1yLCBhW2ldKQoJIyBwcmludChyZXMpCgkjIHByaW50KCI9PT09PT0iKQoJCnByaW50KHJlcyk=