#include using namespace std; #define inf INT_MAX #define INF LLONG_MAX #define ll long long #define ull unsigned long long #define M (int)(1e9+7) #define P pair #define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++) #define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--) #define rep(i,n) FOR(i,0,n) #define rrep(i,n) RFOR(i,n,0) #define all(a) a.begin(),a.end() const int vx[4] = {0,1,0,-1}; const int vy[4] = {1,0,-1,0}; #define F first #define S second #define PB push_back #define EB emplace_back #define int ll #define vi vector #define IP pair #define PI pair #define PP pair #define Yes(f){cout<<(f?"Yes":"No")<>s; map mp; mp[0]=0; int ans=0; int t=0; rep(i,s.size()){ if(s[i]=='A') t++; else t--; if(mp.find(t)!=mp.end()){ //cout<