#pragma region Macros
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define rep2(i,a,b) for(ll i=a;i<=b;++i)
#define rep(i,n) for(ll i=0;i<n;++i)
#define rep3(i,a,b) for(ll i=a;i>=b;--i)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pb push_back
#define eb emplace_back
#define vi vector<int>
#define vec vector<int>
#define vll vector<ll>
#define vpi vector<pii>
#define vpll vector<pll>
#define overload2(_1,_2,name,...) name
#define vv(a,b) vector<vector<int>>(a,vector<int>(b))
#define vv2(a,b,c) vector<vector<int>>(a,vector<int>(b,c))
#define vvl(a,b) vector<vector<ll>>(a,vector<ll>(b))
#define vvl2(a,b,c) vector<vector<ll>>(a,vector<ll>(b,c))
#define vvv(a,b,c) vector<vv(b,c)>(a)
#define vvv2(a,b,c,d) vector<vv(b,c,d)>(a)
#define vvvl(a,b,c) vector<vvl(b,c)>(a)
#define vvvl2(a,b,c,d) vector<vvl(b,c,d)>(a)
#define fi first
#define se second
#define all(c) begin(c),end(c)
#define ios ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define lb(c,x) distance((c).begin(),lower_bound(all(c),(x)))
#define ub(c,x) distance((c).begin(),upper_bound(all(c),(x)))
using namespace std;
template<class T> using pq = priority_queue<T>;
template<class T> using pqg = priority_queue<T,vector<T>,greater<T>>;
#define Size(c) (int)(c).size()
#define INT(...) int __VA_ARGS__;IN(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;IN(__VA_ARGS__)
#define ULL(...) ull __VA_ARGS__;IN(__VA_ARGS__)
#define STR(...) string __VA_ARGS__;IN(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__;IN(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__;IN(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__;IN(__VA_ARGS__)
#define VEC(type,name,size) vector<type> name(size);IN(name)
#define VV(type,name,h,w) vector<vector<type>>name(h,vector<type>(w));IN(name)
int scan(){ return getchar(); }
void scan(int& a){ cin>>a; }
void scan(long long& a){ cin>>a; }
void scan(char &a){cin>>a;}
void scan(double &a){ cin>>a; }
void scan(long double& a){ cin>>a; }
void scan(char a[]){ scanf("%s", a); }
void scan(string& a){ cin >> a; }
template<class T> void scan(vector<T>&);
template<class T, size_t size> void scan(array<T, size>&);
template<class T, class L> void scan(pair<T, L>&);
template<class T, size_t size> void scan(T(&)[size]);
template<class T> void scan(vector<T>& a){ for(auto& i : a) scan(i); }
template<class T> void scan(deque<T>& a){ for(auto& i : a) scan(i); }
template<class T, size_t size> void scan(array<T, size>& a){ for(auto& i : a) scan(i); }
template<class T, class L> void scan(pair<T, L>& p){ scan(p.first); scan(p.second); }
template<class T, size_t size> void scan(T (&a)[size]){ for(auto& i : a) scan(i); }
template<class T> void scan(T& a){ cin >> a; }
void IN(){}
template <class Head, class... Tail> void IN(Head& head, Tail&... tail){ scan(head); IN(tail...); }
string stin() {string s;cin>>s;return s;}
template<class T> inline bool chmax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T> inline bool chmin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
vi iota(int n){vi a(n);iota(all(a),0);return a;}
template<class T> void UNIQUE(vector<T> &x){sort(all(x));x.erase(unique(all(x)),x.end());}
int in() {int x;cin>>x;return x;}
ll lin() {unsigned long long x;cin>>x;return x;}
void print(){putchar(' ');}
void print(bool a){cout<<a;}
void print(int a){cout<<a;}
void print(long long a){cout<<a;}
void print(char a){cout<<a;}
void print(string &a){cout<<a;}
void print(double a){cout<<a;}
template<class T> void print(const vector<T>&);
template<class T, size_t size> void print(const array<T, size>&);
template<class T, class L> void print(const pair<T, L>& p);
template<class T, size_t size> void print(const T (&)[size]);
template<class T> void print(const vector<T>& a){ if(a.empty()) return; print(a[0]); for(auto i = a.begin(); ++i != a.end(); ){ cout<<" "; print(*i); } cout<<endl;}
template<class T> void print(const deque<T>& a){ if(a.empty()) return; print(a[0]); for(auto i = a.begin(); ++i != a.end(); ){ cout<<" "; print(*i); } }
template<class T, size_t size> void print(const array<T, size>& a){ print(a[0]); for(auto i = a.begin(); ++i != a.end(); ){ cout<<" "; print(*i); } }
template<class T, class L> void print(const pair<T, L>& p){ cout<<'(';print(p.first); cout<<","; print(p.second);cout<<')'; }
template<class T> void print(set<T> &x){for(auto e:x)print(e),cout<<" ";cout<<endl;}
template<class T> void print(multiset<T> &x){for(auto e:x)print(e),cout<<" ";cout<<endl;}
template<class T, size_t size> void print(const T (&a)[size]){ print(a[0]); for(auto i = a; ++i != end(a); ){ cout<<" "; print(*i); } }
template<class T> void print(const T& a){ cout << a; }
int out(){ putchar('\n'); return 0; }
template<class T> int out(const T& t){ print(t); putchar('\n'); return 0; }
template<class Head, class... Tail> int out(const Head& head, const Tail&... tail){ print(head); putchar(' '); out(tail...); return 0; }
ll gcd(ll a, ll b){ while(b){ ll c = b; b = a % b; a = c; } return a; }
ll lcm(ll a, ll b){ if(!a || !b) return 0; return a * b / gcd(a, b); }
vector<pll> factor(ll x){ vector<pll> ans; for(ll i = 2; i * i <= x; i++) if(x % i == 0){ ans.push_back({i, 1}); while((x /= i) % i == 0) ans.back().second++; } if(x != 1) ans.push_back({x, 1}); return ans; }
vector<int> divisor(int x){ vector<int> ans; for(int i=1;i*i<=x;i++)if(x%i==0){ans.pb(i);if(i*i!=x)ans.pb(x/i);} return ans;}
int popcount(ll x){return __builtin_popcountll(x);}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int n){return uniform_int_distribution<int>(0, n-1)(rng);}
#define endl '\n'

#ifdef _LOCAL
    #undef endl
    #define debug(x) cout<<#x<<": ";print(x);cout<<endl;
    void err(){}
    template<class T> void err(const T& t){ print(t);  cout<<" ";}
    template<class Head, class... Tail> void err(const Head& head, const Tail&... tail){ print(head); putchar(' '); out(tail...); }
#else
    #define debug(x)
    template<class... T> void err(const T&...){}
#endif

struct Setup_io{ Setup_io(){ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);cout<<fixed<<setprecision(15);}}setup_io;
#pragma endregion


// _______ここから編集！_______________

const int MAX_ROW = 210; // to be set appropriately
const int MAX_COL = 210; // to be set appropriately
struct BitMatrix {
    int H, W;
    bitset<MAX_COL> val[MAX_ROW];
    BitMatrix(int m = 1, int n = 1) : H(m), W(n) {}
    inline bitset<MAX_COL>& operator [] (int i) {return val[i];}
};

int GaussJordan(BitMatrix &A, bool is_extended = false) {
    int rank = 0;
    for (int col = 0; col < A.W; ++col) {
        if (is_extended && col == A.W - 1) break;
        int pivot = -1;
        for (int row = rank; row < A.H; ++row) {
            if (A[row][col]) {
                pivot = row;
                break;
            }
        }
        if (pivot == -1) continue;
        swap(A[pivot], A[rank]);
        for (int row = 0; row < A.H; ++row) {
            if (row != rank && A[row][col]) A[row] ^= A[rank];
        }
        ++rank;
    }
    return rank;
}

int linear_equation(BitMatrix A, vector<int> b, vector<int> &res) {
    int m = A.H, n = A.W;
    BitMatrix M(m, n + 1);
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < n; ++j) M[i][j] = A[i][j];
        M[i][n] = b[i];
    }
    int rank = GaussJordan(M, true);

    // check if it has no solution
    for (int row = rank; row < m; ++row) if (M[row][n]) return -1;

    // answer
    res.assign(n, 0);
    for (int i = 0; i < rank; ++i) res[i] = M[i][n];
    return rank;
}

signed main(){
    STR(s);
    int n = s.size();
    int ok = n,ng = 0;
    while(ok-ng>1){
        int x = (ok+ng)>>1;
        bool flag = false;
        bool FLAG = false;
        rep(i,2)rep(j,2){
            int low = i, high = x-j;
            FLAG = false;
            for(auto e:s){
                if(e == '?'){
                    low--;high++;
                }
                if(e == '0'){
                    low--;high--;
                }
                if(e == '1'){
                    low++;high++;
                }
                if(low<0) low+=2;
                if(high>x) high-=2;
                if(low > high){
                    FLAG = true;
                }
            }
            if(!FLAG) flag = true;
        }
        (flag ? ok : ng) = x;
    }
    cout << ok << endl;
}
                    


Measured memory_bytes: 4296