Nesting "AND" and "OR" Statements

Hello,
I'm trying to create a formula for the following.

IF A1<=B1 AND A2<B2 OR IF A3>=B3, TRUE,FALSE

The following is what I have so far, but I keep getting an error. It's say a parentheses is missing.

IF(AND(A1<=B1,A2<B2),OR(A3>=B3)),TRUE,FALSE)

Any help with formulating this would greatly appreciated. Thank you