ltrominoes.cpp:6:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
6 | main()
| ^~~~
ltrominoes.cpp: In function 'int main()':
ltrominoes.cpp:14:42: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
14 | if((n * m - k) % 6 == 0 || (n % 3) == 0 && n > 3 || (m % 3) && m > 3) cout << "YES" << endl;
| ~~~~~~~~~~~~~^~~~~~~~
ltrominoes.cpp:14:62: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
14 | if((n * m - k) % 6 == 0 || (n % 3) == 0 && n > 3 || (m % 3) && m > 3) cout << "YES" << endl;
| ~~~~~~~~^~~~~~~~