删减

#include<bits/stdc++.h>
using namespace std ; 
typedef long long ll ; 
const int mod = 1e9+ 7 ;
string s1 , s2 , s3 ; 

int main( )
{
    cin >> s1 >> s2 ;
    int l = s2.size( ) ; 
    for( int i = 0 ; i < s1.size( ) ; i++ )
    {
        s3 += s1[i];
        if(s3.size() >= l && s3. substr(s3.size() - l,l) == s2)
        {
            s3.erase(s3.size() - l , l);
        }
    }
    cout << s3 << endl ;
    return 0 ; 
}