Winter D3 A Find the Lost Sock

Alice bought a lot of pairs of socks yesterday. But when she was went home, she found that she had lost one of the them. Each sock has a name which contains exactly 7 charaters.

Alice wants to know which sock she had lost. Maybe can help her.

Input

There is multiple cases. The first line containing a integer n (1 <= n <= 1000000) indicates that Alice bought N Pairs of socks. For the following to1 lines, each line was a string with 7 charaters indicating the name of the socks that Alice Took back.

Output

The name of the lost sock.

Sample Input

2aabcdefbzyxwvubzyxwvu4aqwertyeas FGHAQWERTYEASDFGHEASDFGHAQWERTYAQWERTY20X0ABCD0ABCDEF0X0ABCD

Sample Output

Aabcdefeas Fgh0abcdef

Hint

Because of HUGE input, scanf is recommended.

Method 1:

#include <cstdio> #include <cmath> #include <cstring> #include <stdlib.h>char a[2000005][8];// Note: If you use Qsort to sort a two-dimensional array  , you should use strcmp if  it is not-int cmp (const void *a,const void *b) {    return strcmp ((char*) A, (char*) b);} int main () {    int i,j,k;    int n;    Fast row, detects adjacent strings while    (scanf ("%d", &n)!=-1)    {        getchar ();        for (i=0;i<2*n-1;i++)        gets (A[i]);        Qsort (A,2*n-1,sizeof (a[0]), CMP);        if (strcmp (a[0],a[1])!=0) {printf ("%s\n", a[0]); continue;}        for (i=0;i<2*n-1;i+=2)        if (strcmp (a[i],a[i+1])!=0) {printf ("%s\n", A[i]);    

Method 2: Each string is 7 characters, counting each character of each string with an array if the last character has an odd number of characters, the character is output (get)

Winter D3 A Find the Lost Sock