foo.c: In function 'main':
foo.c:12:13: warning: iteration 6 invokes undefined behavior [-Waggressive-loop-optimizations]
   po[i]=a[i][0]+a[i][1];
         ~~~~^~~
foo.c:10:2: note: within this loop
  for(i=0;i<=6;i++)
  ^~~
foo.c:12:21: warning: array subscript is above array bounds [-Warray-bounds]
   po[i]=a[i][0]+a[i][1];
                 ~~~~^~~
foo.c:26:4: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized]
    printf("%d",t+1);
    ^~~~~~~~~~~~~~~~

自豪地采用[jd5](https://github.com/masnn/jd5)进行评测