Codeforces Round #356 C. Bear and Prime 100

C. Bear and Prime 100

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

This is an interactive problem. In the output section below you will see the information about flushing the output.

Bear Limak thinks of some hidden number — an integer from interval [2, 100]. Your task is to say if the hidden number is prime or composite.

Integer x > 1 is called prime if it has exactly two distinct divisors, 1 and x. If integer x > 1 is not prime, it's called composite.

You can ask up to 20 queries about divisors of the hidden number. In each query you should print an integer from interval [2, 100]. The system will answer "yes" if your integer is a divisor of the hidden number. Otherwise, the answer will be "no".

For example, if the hidden number is 14 then the system will answer "yes" only if you print 2, 7 or 14.

When you are done asking queries, print "prime" or "composite" and terminate your program.

You will get the Wrong Answer verdict if you ask more than 20 queries, or if you print an integer not from the range [2, 100]. Also, you will get the Wrong Answer verdict if the printed answer isn't correct.

You will get the Idleness Limit Exceeded verdict if you don't print anything (but you should) or if you forget about flushing the output (more info below).

Input

After each query you should read one string from the input. It will be "yes" if the printed integer is a divisor of the hidden number, and "no" otherwise.

Output

Up to 20 times you can ask a query — print an integer from interval [2, 100] in one line. You have to both print the end-of-line character and flush the output. After flushing you should read a response from the input.

In any moment you can print the answer "prime" or "composite" (without the quotes). After that, flush the output and terminate your program.

To flush you can use (just after printing an integer and end-of-line):

• fflush(stdout) in C++;
• System.out.flush() in Java;
• stdout.flush() in Python;
• flush(output) in Pascal;
• See the documentation for other languages.

Hacking. To hack someone, as the input you should print the hidden number — one integer from the interval [2, 100]. Of course, his/her solution won't be able to read the hidden number from the input.

Examples

input

yes
no
yes

output

2
80
5
composite

input

no
yes
no
no
no

output

58
59
78
78
2
prime

題意：第一次做交互題，在少於20次詢問中得出該數數素數還是合數,每次系統都會返回yes或者no代表你詢問的這個數是否是該數的因子；

思路：直接詢問2,3,4,5,7,9,11,13,17,19,23,25,29,31,37,41,43,47,49；一共十九次，一開始沒有考慮平方數，錯了好幾次，因爲你循環一次跑完，對於素數的平方數就會錯判成素數，如果該數就是合數，那該數在上述的數中必定有兩個以上是該數的因子。

代碼：

#include<cstdio>  
#include<cstring>  
#include<cstdlib>  
#include<cmath>  
#include<iostream>  
#include<algorithm>  
#include<vector>  
#include<map>  
#include<set>  
#include<queue>  
#include<string>  
#include<bitset>  
#include<utility>  
#include<functional>  
#include<iomanip>  
#include<sstream>  
#include<ctime>  
using namespace std;  

#define maxn int(1e3+20)  
#define inf int(0x3f3f3f3f) 
#define mod int(1e9+7)
#define PI acos(-1.0)
typedef long long ll;
int prime[]={2,3,4,5,7,9,11,13,17,19,23,25,29,31,37,41,43,47,49};
int main()  
{   
#ifdef CDZSC_June  
	freopen("t.txt", "r", stdin);   
#endif 
	char ans[10];
	int p=0;
	for(int i = 0; i<19; i++)
	{
		
		cout<<prime[i]<<endl;
		fflush(stdout);
		cin >> ans;
		if(ans[0] == 'y'){
				p++;
		}
	}
	if(p <=1) cout<<"prime"<<endl;
	else cout<<"composite"<<endl;
	fflush(stdout);
	return 0;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
}