foo.cc: In function 'int main()':
foo.cc:97:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s",op);
   ~~~~~^~~~~~~~~
foo.cc:99:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   if(op[0]=='I'){scanf("%d",&x);change_add(1,l,r,x);}
                  ~~~~~^~~~~~~~~
foo.cc:101:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   else {scanf("%d",&x);printf("%d\n",ask(1,l,r).f[x]);}
         ~~~~~^~~~~~~~~

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