#include #include using namespace std; using namespace atcoder; typedef long long int ll; typedef long double ld; typedef vector vi; typedef vector vl; typedef vector vvl; typedef vector vvvl; typedef vector vvvvl; typedef vector vb; typedef vector vvb; typedef vector vvvb; typedef vector vvvvb; typedef pair pl; typedef pair ppl; typedef pair pppl; typedef pair pppppl; #define rep(i,a,b) for(int i=(a);i<(b);i++) #define rrep(i,a,b) for(int i=(b)-1;i>=(a);i--) #define all(a) begin(a),end(a) #define sz(a) (int)(a).size() #define F first #define S second #define bs(A,x) binary_search(all(A),x) #define lb(A,x) (ll)(lower_bound(all(A),x)-A.begin()) #define ub(A,x) (ll)(upper_bound(all(A),x)-A.begin()) #define cou(A,x) (ll)(upper_bound(all(A),x)-lower_bound(all(A),x)) templateusing min_priority_queue=priority_queue,greater>; templatebool chmax(T&a,T b){if(abool chmin(T&a,T b){if(b vm; typedef vector vvm; typedef vector vvvm; typedef vector vvvvm; ostream&operator<<(ostream&os,mint a){os<>(istream&is,mint&a){int x;is>>x;a=mint(x);return is;} //*/ templateostream&operator<<(ostream&os,pairp){os<istream&operator>>(istream&is,pair&p){is>>p.F>>p.S;return is;} templateostream&operator<<(ostream&os,vectorv){rep(i,0,sz(v))os<istream&operator>>(istream&is,vector&v){for(T&in:v)is>>in;return is;} int main(){ cin.tie(0)->sync_with_stdio(0); cin.exceptions(cin.failbit); ll N;cin>>N; vl A(N),B(N); rep(i,0,N)cin>>A[i]>>B[i]; vl DP(N),EP(N); if(A[0]==B[0])DP[0]=EP[0]=A[0]; rep(i,1,N){ DP[i]=max(DP[i-1]+(B[i-1]==A[i]?A[i]:0),EP[i-1]+(A[i-1]==A[i]?A[i]:0)); EP[i]=max(DP[i-1]+(B[i-1]==B[i]?B[i]:0),EP[i-1]+(A[i-1]==B[i]?B[i]:0)); if(A[i]==B[i])DP[i]+=A[i],EP[i]+=A[i]; } cout<