foo.cc: In function 'int main()':
foo.cc:26:9: warning: unused variable 'last' [-Wunused-variable]
26 | int last = 0;
| ^~~~
foo.cc:25:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
25 | scanf("%d", &N);
| ~~~~~^~~~~~~~~~
foo.cc:28:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
28 | scanf("%d", &stones[i].left);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~
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