**Make It Increasing solution codeforces** – Given 𝑛n integers 𝑎1,𝑎2,…,𝑎𝑛a1,a2,…,an. You can perform the following operation on them:

- select any element 𝑎𝑖ai (1≤𝑖≤𝑛1≤i≤n) and divide it by 22 (round down). In other words, you can replace any selected element 𝑎𝑖ai with the value ⌊𝑎𝑖2⌋⌊ai2⌋ (where ⌊𝑥⌋⌊x⌋ is – round down the real number 𝑥x).

## [Solution] Make It Increasing solution codeforces

Output the minimum number of operations that must be done for a sequence of integers to become strictly increasing (that is, for the condition 𝑎1<𝑎2<⋯<𝑎𝑛a1<a2<⋯<an to be satisfied). Or determine that it is impossible to obtain such a sequence. Note that elements of cannot be swapped. The only possible operation is described above.

For example, let 𝑛=3n=3 and a sequence of numbers [3,6,5][3,6,5] be given. Then it is enough to perform two operations on it:

- Write the number ⌊62⌋=3⌊62⌋=3 instead of the number 𝑎2=6a2=6 and get the sequence [3,3,5][3,3,5];
- Then replace 𝑎1=3a1=3 with ⌊32⌋=1⌊32⌋=1 and get the sequence [1,3,5][1,3,5].

The resulting sequence is strictly increasing because 1<3<51<3<5.

The first line of the input contains an integer 𝑡t (1≤𝑡≤1041≤t≤104) — the number of test cases in the input.

The descriptions of the test cases follow.

The first line of each test case contains a single integer 𝑛n (1≤𝑛≤301≤n≤30).

The second line of each test case contains exactly 𝑛n integers 𝑎1,𝑎2,…,𝑎𝑛a1,a2,…,an (0≤𝑎𝑖≤2⋅1090≤ai≤2⋅109).

## [Solution] Make It Increasing solution codeforces

For each test case, print a single number on a separate line — the minimum number of operations to perform on the sequence to make it strictly increasing. If a strictly increasing sequence cannot be obtained, print “-1“.

7 3 3 6 5 4 5 3 2 1 5 1 2 3 4 5 1 1000000000 4 2 8 7 5 5 8 26 5 21 10 2 5 14

2 -1 0 0 4 11 0

## [Solution] Make It Increasing solution codeforces

The first test case is analyzed in the statement.

In the second test case, it is impossible to obtain a strictly increasing sequence.

In the third test case, the sequence is already strictly increasing.