#include <bits/stdc++.h>
#include <variant>

#define rep2(i,k,n) for(i64 i=(i64)(k);i<(i64)(n);i++)
#define rep(i,n) rep2(i,0,n)
#define all(x) begin(x),end(x)
#ifdef ENV_LOCAL
#define dump if (1) cerr
#else
#define dump if (0) cerr
#endif
 
using namespace std;
using namespace std::string_literals;
 
using i32 = int32_t;
using i64 = int64_t;
using f64 = double;
using f80 = long double;
using vi32 = vector<i32>;
using vi64 = vector<i64>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  vi32 a(3);
  rep(i,3) cin>>a[i];
  sort(all(a));
  if (a[0] == a[2]) {
    cout<<a[0]<<endl;
  } else if (a[0] == a[1]) {
    cout<<a[2]<<endl;
  } else if (a[1] == a[2]) {
    cout<<a[0]<<endl;
  } else {
    i32 ans = 6;
    rep(i,3) ans -= a[i];
    cout<<ans<<endl;
  }
  return 0;
}