# Enter your code here. Read input from STDIN. Print output to STDOUT
n=int(raw_input())
arr=map(str,raw_input().strip())
l=0
j=0
for i in range(0,n):
    c=0
    c=c+j
    if arr[i]=="D":
        j=j-1
    else:
        j=j+1
    
    if j==0 and c<0: l=l+1
print l