foo.c: In function 'main':
foo.c:6:1: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d%d",&m,&n);
 ^~~~~~~~~~~~~~~~~~~
foo.c:12:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&a[i][j]);
    ^~~~~~~~~~~~~~~~~~~~
foo.c:31:5: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
 if(a[y][k]>x)return 0;
     ^
foo.c:24:10: note: 'y' was declared here
 {int i=0,y;
          ^
foo.c: In function 'andian':
foo.c:31:5: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
 if(a[y][k]>x)return 0;
     ^

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