foo.cc: In function 'int main()':
foo.cc:29:24: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   29 |             int mid=l+r+1>>1;
      |                     ~~~^~
foo.cc:21:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |     scanf("%d",&T);
      |     ~~~~~^~~~~~~~~
foo.cc:24:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   24 |         scanf("%d",&n);
      |         ~~~~~^~~~~~~~~
foo.cc:25:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   25 |         for(int i=1;i<=n;i++) scanf("%d%d",&a[i],&b[i]);
      |                               ~~~~~^~~~~~~~~~~~~~~~~~~~

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