Score : 200 points
You have an integer variable x. Initially, x=0.
Some person gave you a string S of length N, and using the string you performed the following operation N times.
In the i-th operation, you incremented the value of x by 1 if S_i=I
, and decremented the value of x by 1 if S_i=D
.
Find the maximum value taken by x during the operations (including before the first operation, and after the last operation).
I
and D
occur in S.The input is given from Standard Input in the following format:
N S
Print the maximum value taken by x during the operations.
5 IIDID
2
After each operation, the value of x becomes 1, 2, 1, 2 and 1, respectively. Thus, the output should be 2, the maximum value.
7 DDIDDII
0
The initial value x=0 is the maximum value taken by x, thus the output should be 0.