#include <cstdio>
//--------------------------------------------
int  tcase;
int  icase;

int  n;
int  i,j;

int  ans;
//--------------------------------------------
int  main()
{
//    freopen( "xx.in"  , "r" , stdin  );
//    freopen( "xx.out" , "w" , stdout );

    //--0 init    
    for (scanf("%d",&tcase); ++icase<=tcase; )
    {
        ans=0;
        scanf("%d",&n);
        for (i=1; i<=n; i++)
        {
            scanf("%d",&j);
            if (ans < j)
                ans = j;
        }
        printf("%d\n",ans);
    }
    


}