foo.c: In function 'main':
foo.c:25:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&up[i]);
   ^~~~~~~~~~~~~~~~~~
foo.c:27:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&cost[i][j]);
    ^~~~~~~~~~~~~~~~~~~~~~~