#include <cstdio>

using namespace std;
bool f[26];

int main()
{
    int n, i, ii, cnt;
    char ch, prev;
    scanf("%d\n", &n);
    for(ii = 1; ii <= n; ii++) {
        prev = '\n';
        cnt = 0;
        while(scanf("%c", &ch) != EOF && ch != '\n') {
            if(prev == '\n')
            {
                cnt = 1;
                prev = ch;
                continue;
            }
            if(ch != prev) {
                if(cnt & 1) {
                    f[prev - 'a'] = true;
                }
                prev = ch;
                cnt = 1;
                continue;
            }
            cnt++;
        }
        if(cnt & 1)
            f[prev - 'a'] = true;
        for(i = 0; i <= 25; i++) {
            if(f[i])
                printf("%c", 'a' + i);
            f[i] = false;
        }
        printf("\n");
    }
    return 0;
}