Debts#11300
Alice now has hryvnias. She remembers that Petya owes her hryvnias, Svetlana owes her hryvnias. However, Alice owes Roma hryvnia.
If everyone repays their debts, how many hryvnias will Alice have?
The first line contains one integer (1 \leq a \leq 100) - the amount of hryvnias that Alice has.
The second line contains a single integer (1 \leq b \leq 100) - the amount of hryvnia that Petya owes Alice.
The third line contains a single integer (1 \leq c \leq 100) - the amount of hryvnia that Svetlana owes Alice.
The fourth line contains a single integer (1 \leq d \leq 100) - the amount of hryvnias that Alice owes Roma.
It is guaranteed that Alice will end up with a non-negative amount of hryvnias.
Print one integer - the amount of hryvnias that Alice will have.
Example 1
Example 2