Codeforces Global Round 27 |
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Finished |
Given a positive integer n. Find the smallest integer whose decimal representation has length n and consists only of 3s and 6s such that it is divisible by both 33 and 66. If no such integer exists, print −1.
The first line contains a single integer t (1≤t≤500) — the number of test cases.
The only line of each test case contains a single integer n (1≤n≤500) — the length of the decimal representation.
For each test case, output the smallest required integer if such an integer exists and −1 otherwise.
6123457
-1 66 -1 3366 36366 3336366
For n=1, no such integer exists as neither 3 nor 6 is divisible by 33.
For n=2, 66 consists only of 6s and it is divisible by both 33 and 66.
For n=3, no such integer exists. Only 363 is divisible by 33, but it is not divisible by 66.
For n=4, 3366 and 6666 are divisible by both 33 and 66, and 3366 is the smallest.
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