Global Positioning System (GPS) is based on nnn artificial satellites, where each satellite has a 3D-coordinates (x,y,z)(x,y,z)(x,y,z). Since the coordinates are always changing, we can hardly know the exact value of the coordinates, even if the satellites are relative static to each other.
To get more information about their coordinate, we still try every effort to do mmm measurements. For each measurement, we choose the uuu-th and the vvv-th satellites, and measure the coordinate difference between them. Specifically, we will get (xv−xu,yv−yu,zv−zu)(x_v - x_u, y_v - y_u, z_v - z_u)(xv−xu,yv−yu,zv−zu) after the measurement of them. With these mmm measurement results, we can now know the coordinate difference between any two satellites.
However, lzr010506 has the impression that he has mistaken exactly one measurement result, so there may exist no possible coordinates to match all the measurements for the satellites for now. You need to find out all the measurements results that might be mistaken, so he can try to fix it as soon as possible.
Here a measurement result might be mistaken iff there exist possible coordinates to match all the measurements after modifying the mistaken measurement result to the one other than the original one.