#include <iostream>
	using namespace std; 
	
	const int MAX = 36;
	const int PRINT_MIN = 20;
	const int PRINT_MAX = 50;
	
	
	// Returns a string of random alphabets of 
	// length n. 
	string printRandomString(int n) 
	{ 
	    char alphabet[MAX] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 
	                        'H', 'I', 'J', 'K', 'L', 'M', 'N', 
	                        'O', 'P', 'Q', 'R', 'S', 'T', 'U', 
	                        'V', 'W', 'X', 'Y', 'Z', '0', '1', '2',
	                        '3', '4', '5', '6', '7', '8', '9'}; 
	
	    string res = "";
	    for (int i = 0; i < n; i++) 
	        res = res + alphabet[rand() % MAX]; 
	    
	    return res; 
	} 
	
	// Driver code 
	int main() 
	{ 
		srand(time(NULL)); 
	    int len = PRINT_MIN + ( rand() % ( PRINT_MAX - PRINT_MIN + 1 ) );
	    for(int i = 0; i< len; i++)
	    {
	    	int n = PRINT_MIN + ( rand() % ( PRINT_MAX - PRINT_MIN + 1 ) );
			cout << printRandomString(n)<<endl;
	    } 
		return 0; 
	}