The Challenge Day

It is the end of 2019 — the 17th of November, the Cooking Challenge day. There are $N$ players participating in this competition, numbered $1$ through $N$. Initially, the skill level of each player is zero. There are also $M$ challenges (numbered $1$ through $M$). For each valid $i$, the $i$-th challenge has three parameters $L_i$, $R_i$ and $X_i$ with the following meaning: for each player bet