#include <bits/stdc++.h>
using namespace std;
string a;
bool check(int x) {
  int fla = 0;
  if (a[x] == 'A' || a[x + 1] == 'A' || a[x + 2] == 'A') fla++;
  if (a[x] == 'B' || a[x + 1] == 'B' || a[x + 2] == 'B') fla++;
  if (a[x] == 'C' || a[x + 1] == 'C' || a[x + 2] == 'C') fla++;
  if (fla == 3)
    return 1;
  else
    return 0;
}
int main() {
  cin >> a;
  int len = a.size();
  for (int i = 0; i < len - 2; i++) {
    if (check(i)) {
      cout << "yes" << endl;
      return 0;
    }
  }
  cout << "no" << endl;
  return 0;
}
