#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define int ll
#define rep(i,a,b) for(int i = a; i < (b); i++)
#define all(x) begin(x), end(x)
#define sz(s) (int)(x).size()
#define PB push_back
#define cmx(x, y) x = max(x, y)
#define cmn(x, y) x = min(x, y)
typedef pair<int, int> pii;
typedef vector<int> vi;
string s;
int n,x,y;
signed main() {
	cin.tie(0)->sync_with_stdio(0); cin.exceptions(cin.failbit);
    cin>>s,n=s.size(),s=' '+s;
    for(int i=1;i<=n;i++)
        x+=s[i]=='W',y+=s[i]=='B';
    cout<<(x==y)<<'\n';
}