Codeforces Round #163 (Div. 2) A. Stones on the Table

#include <iostream>

using namespace std;
char arr[55];
int main()
{
int n;
cin>>n;
for(int i=0;i<n;i++)
{
cin>>arr[i];
}
int ans=0;

for(int i=0;i<n;i++)
{
if(arr[i]==arr[i+1]) ans++;
}
cout << ans;
return 0;
}