/in/foo.cc: In function 'int mian()':
/in/foo.cc:20:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc:15:20: warning: array subscript is above array bounds [-Warray-bounds]
    for(int k=a[p][0];k<=p;k++)
              ~~~~~~^
/in/foo.cc:16:18: warning: array subscript is above array bounds [-Warray-bounds]
  {int temp=a[p][k];
            ~~~~~~^
/usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
collect2: error: ld returned 1 exit status