import java.util.*; public class Main{ public static void main(String[] args) { Scanner sc = new Scanner(System.in); String[] v = sc.next().split(","); int[] dp = new int[v.length+1]; dp[0] = Integer.parseInt(v[0]); dp[1] = Integer.parseInt(v[1]); for(int i=2;i<v.length;++i) { int cur = Integer.parseInt(v[i]); dp[i] = cur + min(dp[i-1],dp[i-2] ); } System.out.println(min(dp[v.length-1],dp[v.length-2])); } public static int min(int... a) { return Arrays.stream(a).min().getAsInt(); } }