foo.cc: In function 'int main()':
foo.cc:28:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%s",s+i*20);
             ~~~~~^~~~~~~~~~~~~
foo.cc:29:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&c);
         ~~~~~^~~~~~~~~
foo.cc:31:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%s",d[i]);
             ~~~~~^~~~~~~~~~~

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