contract ExampleContract {

	function containsAThree(uint256[][] calldata nestedArray) public pure returns (bool) {

		for (uint256 i = 0; i < nestedArray.length; i++) {
			for (uint256 j = 0; j < nestedArray[0].length; j++) {
				if (nestedArray[i][j] == 3) {
					return true;
				}
			}
		}
		return false;
	}
}