Codeforces Round #440 (Div. 2, based on Technocup 2018 Elimination Round 2) C. Maximum splitting

时间:2023-03-10 06:31:47
Codeforces Round #440 (Div. 2, based on Technocup 2018 Elimination Round 2) C. Maximum splitting

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题目:

C. Maximum splitting
time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

You are given several queries. In the i-th query you are given a single positive integer ni. You are to represent ni as a sum of maximum possible number of composite summands and print this maximum number, or print -1, if there are no such splittings.

An integer greater than 1 is composite, if it is not prime, i.e. if it has positive divisors not equal to 1 and the integer itself.

Input

The first line contains single integer q (1 ≤ q ≤ 105) — the number of queries.

q lines follow. The (i + 1)-th line contains single integer ni (1 ≤ ni ≤ 109) — the i-th query.

Output

For each query print the maximum possible number of summands in a valid splitting to composite summands, or -1, if there are no such splittings.

Examples
input
1
12
output
3
input
2
6
8
output
1
2
input
3
1
2
3
output
-1
-1
-1
Note

12 = 4 + 4 + 4 = 4 + 8 = 6 + 6 = 12, but the first splitting has the maximum possible number of summands.

8 = 4 + 4, 6 can't be split into several composite summands.

1, 2, 3 are less than any composite number, so they do not have valid splittings.

思路:

  最小合数是4,所以用4去凑就行了

 #include <bits/stdc++.h>

 using namespace std;

 #define MP make_pair
#define PB push_back
typedef long long LL;
typedef pair<int,int> PII;
const double eps=1e-;
const double pi=acos(-1.0);
const int K=1e6+;
const int mod=1e9+; int main(void)
{
int n,x,ans;cin>>x;
while(x--)
{
scanf("%d",&n);
if(n%==)
ans=n/;
else if(n%==)
{
if(n<)
ans=-;
else if(n==)
ans=;
else
ans=(n-)/+;
}
else if(n%==)
{
if(n<)
ans=-;
else if(n==)
ans=;
else
ans=n/;
}
else
{
if(n<)
ans=-;
else
ans=(n-)/+;
}
printf("%d\n",ans);
}
return ;
}