#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  vector<char> ans;
  for (int i = 0; i < s.length();) {
    if (s[i] == '@') {
      ans.push_back(s[i]);
      if (i + 1 < s.length()) {
        ans.push_back(s[i + 1]);
      }
      for (int j = i + 2; j < s.length(); j++) {
        if (s[j] == '@') {
          ans.push_back(',');
          break;
        }
      }
      i = i + 2;
    } else {
      ans.push_back(s[i]);
      i++;
    }
  }
  bool ok = true;
  if (s[0] == '@' || s[s.length() - 1] == '@') {
    ok = false;
  }
  int num = 0;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] == '@') {
      num++;
      if (i + 1 < s.length()) {
        if (s[i + 1] == '@') {
          ok = false;
        }
      }
      if (i + 2 < s.length()) {
        if (s[i + 2] == '@') {
          ok = false;
        }
      }
    }
  }
  if (num == 0) {
    ok = false;
  }
  if (ok == false) {
    cout << "No solution" << endl;
  } else {
    for (int i = 0; i < ans.size(); i++) {
      cout << ans[i];
    }
    cout << endl;
  }
  return 0;
}
