import java.util.Arrays; import java.util.Scanner; public class Zero {     public static void main(String[] args) {         Scanner input = new Scanner(System.in);         String s = input.nextLine().trim();         String[] str = s.split(",");         int[] sum = new int[str.length];         for (int i = 0; i < str.length; i++) {             sum[i] = Integer.valueOf(str[i]);         }         int number = 0;         Arrays.sort(sum);         int i = 0, j = sum.length - 1;         while (i < j) {             while (i < sum.length - 1 && sum[i] == sum[i + 1]) {                 i++;             }             while (j > 0 && sum[j] == sum[j - 1]) {                 j--;             }             int temp = sum[i] + sum[j];             if (temp == 0) {                 number++;                 i++;                 j--;             } else if (temp > 0) {                 j--;             } else {                 i++;             }         }  //下面代码超时 /*        for (int i = 0; i < str.length; i++) {             int num = -sum[i];             boolean sign = false;             for (int j = i + 1; j < str.length; j++) {                 if (num == sum[j]) {                     if (!sign) {                         number++;                         sign = true;                     }                     sum[j] = sum[i];                 }             }         }*/                  System.out.println(number);     } }