CREATE TABLE test (c1 NUMBER, c2 NUMBER);
INSERT INTO test (c1, c2) VALUES (1, 1), (2, 1), (3, 1), (4, 2);
UPDATE test SET c2 = c1;
DELETE FROM test WHERE c1 = 1;
SELECT SUM(c2) FROM test;

CREATE TABLE test (c1 NUMBER, c2 NUMBER);
INSERT INTO test (c1, c2) VALUES (1, 1), (2, 1), (3, 1), (4, 2);
UPDATE test SET c2 = c1;
DELETE FROM test WHERE c1 = 1;
SELECT SUM(c2) FROM test;

What is the result of the final SELECT SUM(c2) FROM test; statement?