23. Five schoolchildren participated in a cycling race. Before the race, four fans made the following assumptions about the distribution of places: 1) Sergey will take second place, and Kolya third; 2) Nadya will take third place, and Tolya fifth; 3) Tolya will take first place, and Nadya second; 4) Sergey will take second place, and Vanya fourth. After the race, it turned out that in each of these assumptions, one part was correct, and the other incorrect. How did the places among the schoolchildren turn out?
23. 1st place was taken by Sergei, 2nd - Nadya, 3rd - Kolya, 4th - Vanya, 5th - Tolya.