foo.cc: In function 'int main()':
foo.cc:112:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  112 |   scanf("%d%d",&n,&m);
      |   ~~~~~^~~~~~~~~~~~~~
foo.cc:114:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  114 |     scanf("%d",&x);
      |     ~~~~~^~~~~~~~~
foo.cc:119:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  119 |   for(i=1;i<n;i++)scanf("%d%d",&x,&y),add(x,y),add(y,x);
      |                   ~~~~~^~~~~~~~~~~~~~
foo.cc:123:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  123 |   scanf("%d",&Q);
      |   ~~~~~^~~~~~~~~
foo.cc:125:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  125 |     scanf("%s%d",op,&x);
      |     ~~~~~^~~~~~~~~~~~~~
foo.cc:127:12: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  127 |       scanf("%d",&y);
      |       ~~~~~^~~~~~~~~

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