#include <iostream> #include <vector> using namespace std; int matchsticks[10] = {6, 2, 5, 5, 4, 5, 6, 3, 7, 6}; // 0~9的火柴数 int count_equations(int n) { int count = 0; for (int a = 0; a <= n - 4; ++a) { // A最多占n-4根 for (int b = 0; b <= n - 4; ++b) { // B最多占n-4根 int c = a + b; if (matchsticks[a] + matchsticks[b] + matchsticks[c] + 4 == n) { count++; } } } return count; } int main() { int n; cin >> n; cout << count_equations(n) << endl; return 0; }