foo.c: In function 'main':
foo.c:7:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%ld%c%ld",&length,&space,&room);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:12:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%ld%c%ld%c",&begin,&space,&end,&space);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:19:16: warning: 'sum' may be used uninitialized in this function [-Wmaybe-uninitialized]
             sum++;
             ~~~^~

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