#include #include using namespace std; using namespace atcoder; typedef int64_t lint; #define rep(i, n) for(int i=0; i; using vvi = vector>; template inline void vin(vector& v) { rep(i, v.size()) cin >> v.at(i); } template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } template inline void drop(T x) { cout << x << endl; exit(0); } template void vout(vector v) { rep(i, v.size()) { cout << v.at(i) << ' '; } cout << endl; } constexpr lint LINF = LLONG_MAX/2; using pint = pair; using vp = vector; int main() { lint N; cin >> N; vi v(N); vin(v); v.pb(0); v.pb(0); lint a=0, b=0, c=0, x, y, z; vi w(N+2); stack s; rep(i, N+2) { if (i%2 == 0) { w[i] = v[i]-(a+b); a += w[i]; if (a < 0) drop("No"); } else { w[i] = v[i]-(a+b); b += w[i]; if (b < 0) drop("No"); if (w[i] > 0) s.push({w[i], a%2}); else { x = -w[i]; while (x > 0) { tie(y, z) = s.top(); s.pop(); if (z != a%2) drop("No"); if (x < y) { s.push({y-x, z}); x = 0; } else { x -= y; } } } } } // repx(i, 1, N) w[i] += w[i-1]; // rep(i, N) { // if (v[i] != w[i]) drop("No"); // } std::cout << "Yes" << '\n'; }