#include <stdio.h>#include <string.h>#include <algorithm> using namespace std; int main() { int n; scanf("%d", &n); bool a[n][n]; memset(a, true, sizeof(a)); int m; scanf("%d", &m); for (int k = 0; k < m; ++k) { int x, y, aa; scanf("%d%d%d", &x, &y, &aa); for (int i = x; i < min(x + aa, n + 1); ++i) { for (int j = y; j < min(y + aa, n + 1); ++j) { a[i][j] = false; } } } int cnt = 0; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (a[i][j]) { cnt++; } } } printf("%d", cnt); return 0;}