#include <bits/stdc++.h>
using namespace std;
int main() {
  string in;
  cin >> in;
  string x = "2013", y = "2014", z = "2015";
  map<string, int> X;
  for (int i = 0; i < in.size(); i++) {
    string temp = in.substr(i, 4);
    if (strcmp(temp.c_str(), x.c_str()) == 0) {
      temp = in.substr(i - 6, 10);
      if (X.find(temp) == X.end()) {
        X[temp] = 1;
      } else
        X[temp]++;
    }
    if (strcmp(temp.c_str(), y.c_str()) == 0) {
      temp = in.substr(i - 6, 10);
      if (X.find(temp) == X.end()) {
        X[temp] = 1;
      } else
        X[temp]++;
    }
    if (strcmp(temp.c_str(), z.c_str()) == 0) {
      temp = in.substr(i - 6, 10);
      if (X.find(temp) == X.end()) {
        X[temp] = 1;
      } else
        X[temp]++;
    }
  }
  map<string, int>::iterator it, ret;
  int max = 0;
  for (it = X.begin(); it != X.end(); it++) {
    if ((*it).second > max) {
      max = (*it).second;
      ret = it;
    }
  }
  cout << (*ret).first << endl;
  return 0;
}
