/** * author: otera **/ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define int long long typedef long long ll; typedef unsigned long long ul; typedef unsigned int ui; typedef long double ld; const int inf=1e9+7; const ll INF=1LL<<60 ; const ll mod=1e9+7 ; #define rep(i,n) for(int i=0;i=0;i--) #define Rep(i,sta,n) for(int i=sta;i=1;i--) #define Rep1(i,sta,n) for(int i=sta;i<=n;i++) typedef complex Point; const ld eps = 1e-8; const ld pi = acos(-1.0); typedef pair P; typedef pair LDP; typedef pair LP; #define fr first #define sc second #define all(c) c.begin(),c.end() #define pb push_back #define debug(x) cerr << #x << " = " << (x) << endl; 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; } void solve() { int n; cin >> n; vector a(n); rep(i, n) { cin >> a[i]; } vector> dp(n + 1, vector(10, -inf)); dp[0][0] = 0; rep(i, n) { rep(j, 10) { chmax(dp[i + 1][j], dp[i][j]); chmax(dp[i + 1][(j + a[i]) % 10], dp[i][j] + 1); } } cout << dp[n][0] << endl; } signed main() { ios::sync_with_stdio(false); cin.tie(0); //cout << fixed << setprecision(10); //int t; cin >> t; rep(i, t)solve(); solve(); return 0; }