| Subtask no. | Testdata Range | Constraints | Score | 
|---|---|---|---|
| 1 | 0~1 | 範例測資 | 0 / 0 | 
| 2 | 2~8 | $\forall 1 \leq i \leq M,\ s_i=t_i=i$ | 1 / 1 | 
| 3 | 9~27 | $M=N-1$,$\forall 1 \leq i < M,\ u_i=i,\ v_i=i+1$ | 9 / 9 | 
| 4 | 28~35 | $N \leq 50, M \leq 100$ | 40 / 40 | 
| 5 | 28~46 | $N \leq 200, M \leq 1000$ | 30 / 30 | 
| 6 | 2~70 | 無額外限制 | 0 / 20 |