118. Digital Root¶
time limit per test: 0.25 sec / memory limit per test: 4096 KB
Let f(n) be a sum of digits for positive integer n. If f(n) is one-digit number then it is a digital root for n and otherwise digital root of n is equal to digital root of f(n). For example, digital root of 987 is 6. Your task is to find digital root for expression \(A_1*A_2*…*A_N + A_1*A_2*…*A_{N-1} + … + A_1*A_2 + A_1.\)
Input
Input file consists of few test cases. There is K (1<=K<=5) in the first line of input. Each test case is a line. Positive integer number N is written on the first place of test case (N<=1000). After it there are N positive integer numbers (sequence A). Each of this numbers is non-negative and not more than \(10^9\).
Output
Write one line for every test case. On each line write digital root for given expression.
Example(s)
| Sample Input | Sample Output |
1
3 2 3 4
|
5
|
| Author | Resource | Date |
|---|---|---|
| : Michael R. Mirzayanov | : PhTL #1 Training Contests | : Fall 2001 |