Nathan is a big fan of recreational mathematics. For one of his problems, he needs to add together very large numbers. He created a class called BigInteger
to help with the adding, but he isn't done yet! Nathan needs to stress test his code, so he devised the following problem.
There will be
0
to9
: Add this digit to the end of the current number. Afterwards, add the current number to the total.-
: Remove the last digit from the current number. It is guaranteed that the current number will not be empty after this instruction. Afterwards, add the current number to the total.
At the beginning, the total is
Input Specification
The first line will contain the integer
The second line will contain a string of length 0123456789-
.
Constraints
In all subtasks,
Subtask | Points | Additional Constraints |
---|---|---|
1 | 5 | |
2 | 15 | After each instruction, there will be at most one non-zero digit in the current number. |
3 | 20 | The instruction - will not appear. |
4 | 40 | |
5 | 20 | No additional constraints. |
Output Specification
Print the total. Leading zeroes will be ignored by the checker. If your program does not print anything, the total is assumed to be
Sample Input 1
8
0100---5
Sample Output 1
00000127
Explanation for Sample Output 1
Notice that leading zeroes are allowed in the output.
Sample Input 2
4
1817
Sample Output 2
2017
Explanation for Sample Output 2
The numbers to be added are
Sample Input 3
2
0-
Sample Output 3
00
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