codeforces 1203D2（贪心）

#include<bits/stdc++.h>
#define x first
#define y second
#define PB push_back
#define mst(x,a) memset(x,a,sizeof(x))
#define all(a) begin(a),end(a)
#define rep(x,l,u) for(ll x=l;x<u;x++)
#define rrep(x,l,u) for(ll x=l;x>=u;x--)
#define sz(x) x.size()
#define ins(x) inserter(x,x.begin())
#define IOS ios::sync_with_stdio(false);cin.tie(0);
using namespace std;
typedef unsigned long long ull;
typedef pair<int,int> PII;
typedef pair<long,long> PLL;
typedef pair<char,char> PCC;
typedef long long ll;
const int N=4*1e5+10;
const int M=1e6+10;
const int INF=0x3f3f3f3f;
const int MOD=1e9+7;
/*独立思考
不要看测试样例
找性质
试着证明
写完后不盲目交，检查*/
string s,t;
int Left[N],Right[N];
void solve(){
    cin>>s>>t;
    int len1=sz(s),len2=sz(t);
    int idx=0;
    rep(i,0,len1){
        if(s[i]==t[idx]){
            Left[idx]=i;
            idx++;
        }
        if(idx==len2) break;
    }
    idx=0;
    rrep(i,len1-1,0){
        if(s[i]==t[len2-idx-1]){
            Right[idx]=i;
            idx++;
        }
        if(idx==len2) break;
    }
    int ans=max(len1-Left[len2-1]-1,Right[len2-1]);
    rep(i,0,len2-1){
        ans=max(ans,Right[i]-Left[len2-i-2]-1);
    }
    cout<<ans<<endl;
}
int main(){
    IOS;
    //int t;cin>>t;
    //while(t--){
        solve();
    //}
    return 0;
}