#include<iostream> using namespace std; int main(){ cout<<1 * 2 + 2 * 3 + 3 * 4 + 4 * 5 + 5 * 6 + 6 * 7 + 7 * 8 + 8 * 9 + 9 * 10 + 10 * 11; } return 0; }