#include <bits/stdc++.h>
using namespace std;
int main() {
  char email[205], sep[205];
  vector<string> solution;
  int len, i, j, flag, arr[205], first, index;
  while (scanf("%s", email) == 1) {
    len = strlen(email);
    index = 0;
    if (len == 1) {
      printf("No solution\n");
      continue;
    }
    for (i = 0; i < len; i++) {
      if (email[i] == '@') arr[index++] = i;
    }
    flag = 1;
    for (i = 0; i < index - 1; i++) {
      if ((arr[i + 1] - arr[i] == 1) || (arr[i + 1] - arr[i] == 2)) {
        flag = 0;
        break;
      }
    }
    if (flag == 0 || email[0] == '@' || email[len - 1] == '@' || index == 0)
      printf("No solution\n");
    else if (flag == 1) {
      solution.clear();
      index = 0;
      first = 0;
      for (i = 0; i < len; i++) {
        if (email[i] != '@')
          sep[index++] = email[i];
        else if (email[i] == '@') {
          if (first == 1) {
            sep[index - 1] = '\0';
            solution.push_back(sep);
            index = 0;
            sep[index++] = email[i - 1];
            sep[index++] = email[i];
          } else if (first == 0) {
            sep[index++] = email[i];
            first = 1;
          }
        }
      }
      sep[index] = '\0';
      solution.push_back(sep);
      len = solution.size();
      for (i = 0; i < len; i++) {
        cout << solution[i];
        if (i != len - 1) printf(",");
      }
      printf("\n");
    }
  }
  return 0;
}
