foo.cc: In function 'int main()':
foo.cc:123:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
foo.cc:124:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d%d", &Sx, &Sy, &Tx, &Ty);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:126:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d%d%d", &ice[i].x1, &ice[i].y1, &ice[i].x2, &ice[i].y2);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~