#include <bits/stdc++.h> using namespace std; struct ListNode { int val; ListNode* next; ListNode() : val(0), next(nullptr) {} ListNode(int x) : val(x), next(nullptr) {} ListNode(int x, ListNode *next_) : val(x), next(next_) {} }; int main() { int a, b, c; stack<ListNode*> m; while(cin &...