func_code_string: #include<bits/stdc++.h>   #define fast_io ios_base::sync_with_stdio(false);cin.tie(NULL);   #define int long long   #define ull unsigned long long   #define FOR(i,a,b) for(int i=a;i<b;i++)   #define all(x) (x).begin(), (x).end()   #define pb push_back   #define mp make_pair   #define in insert   #define ff first   #define ss second   #define endl   n    #define pi pair<int,int>   #define  deb1(a)         cout<<a<<  n ;   #define  deb2(a,b)       cout<<a<<   <<b<<  n ;   #define  deb3(a,b,c)     cout<<a<<   <<b<<   <<c<<  n ;   #define  debp(a)         cout<<a.ff<<   <<a.ss<<  n ;   #define  debvec(a)      for(auto it: a)cout<<it<<   ;cout<<   ; cout<<endl;   #define  debvp(a)      for(auto it: a)cout<<it.ff<<   <<it.ss<<endl;   #define  debmap(a)      for(auto it: a)cout<< { <<it.ff<< , <<it.ss<< },  ;newl;   #define  debarr(a,n)    FOR(i,0,n)cout<<a[i]<<   ;cout<<endl;   #define inf ((int)1<<60)   #define mod 1000000007   using namespace std;   //int,char,float,double,bool,string,break,continue,endl,if,else,set,multiset,multimap,unordered_map,unordered_set,cout,cin,printf,scanf   //strlen,strcmp,compar e,auto,while,return,true,false,sizeof,size,abs,INT_MAX,INT_MIN,itr,it,sort,YES,NO      signed main() {   #ifndef ONLINE_JUDGE    freopen( input.txt ,  r , stdin);    freopen( output.txt ,  w , stdout);   #endif    fast_io    int test, i, j;   //  cin >> test;    test = 1;    while (test--) {     int n, m;     cin >> n >> m;     string s, t;     cin >> s >> t;     int a[m], b[m];     j = 0;     for (int i = 0; i < n; ++i) {      if (s[i] == t[j]) {       a[j] = i;       j++;      }     }     j = m - 1;     for (int i = n - 1; i >= 0 ; i--) {      if (s[i] == t[j]) {       b[j] = i;       j--;      }     }     int ans = 0;     for (int i = 0; i < m - 1; ++i) {      ans = max(ans, b[i + 1] - a[i]);     }     cout << ans << endl;    }      }