codeforces#P1512G. Short Task
Short Task
Description
Let us denote by $d(n)$ the sum of all divisors of the number $n$, i.e. $d(n) = \sum\limits_{k | n} k$.
For example, $d(1) = 1$, $d(4) = 1+2+4=7$, $d(6) = 1+2+3+6=12$.
For a given number $c$, find the minimum $n$ such that $d(n) = c$.
The first line contains one integer $t$ ($1 \le t \le 10^4$). Then $t$ test cases follow.
Each test case is characterized by one integer $c$ ($1 \le c \le 10^7$).
For each test case, output:
- "-1" if there is no such $n$ that $d(n) = c$;
- $n$, otherwise.
Input
The first line contains one integer $t$ ($1 \le t \le 10^4$). Then $t$ test cases follow.
Each test case is characterized by one integer $c$ ($1 \le c \le 10^7$).
Output
For each test case, output:
- "-1" if there is no such $n$ that $d(n) = c$;
- $n$, otherwise.
Samples
12
1
2
3
4
5
6
7
8
9
10
39
691
1
-1
2
3
-1
5
4
7
-1
-1
18
-1