#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using ll=long long; #define int ll #define rng(i,a,b) for(int i=int(a);i=int(a);i--) #define per(i,b) gnr(i,0,b) #define eb emplace_back #define all(x) x.begin(),x.end() #define SZ(x) ((int)x.size()) #define fi first #define se second const int INF = 1e15; using namespace std; template using vc=vector; template using vvc=vc>; using pi=pair; using vi=vc; template inline bool chmax(T &a,T b){if(a inline bool chmin(T &a,T b){if(a>b){a=b;return true;}return false;} int cnt[10]; int dp[2][10]; signed main() { cin.tie(0); ios::sync_with_stdio(0); cout<> N; int A[N]; rep(i,N) cin >> A[i]; rep(i,N) { rep(j,10) { if(j>0 && dp[i%2][j]==0) continue; chmax(dp[1][(j+A[i])%10],dp[0][j]+1); } rep(j,10) { dp[0][j]=dp[1][j]; } } cout << dp[0][0] << endl; }