#pragma GCC optimize(3,"Ofast","inline")
#include <bits/stdc++.h>
using namespace std;
#define int long long
inline int read()
{
	char ch=getchar();
	int x=0,m=1;
	while(!isdigit(ch)){
		if (ch=='-') m=-1;
		ch=getchar();
	}
	while(isdigit(ch)){
		x=x*10+ch-'0';
		ch=getchar();
	}
	return x*m;
}
inline void write(int x)
{
	if (x<0) putchar('-'),x=-x;
	if (x>=10) write(x/10);
	putchar(x%10+'0');
}
int n,t;
string s;
char a,b,c;
signed main()
{
	int m(read());
	for (int qwq=1;qwq<=m;qwq++){
		s="";
		int n=-1;
		char ch=getchar();
		while(ch=='\n') ch=getchar();
		while(ch!='\n'){
			s[++n]=ch;
			ch=getchar();
		}
	    cin>>a;
	    if(a=='D'){
	        bool p(false);
	        cin>>b;
	        t=0;
	        while(s[t]!=b&&t<=n){
				t++;
				if (s[t]==b) p=true;
			}
			if (!p){
				puts("error");
				continue;
			}
			for (int i=0;i<t;i++) putchar(s[i]);
			for (int i=t+1;i<=n;i++) putchar(s[i]);
			putchar('\n');
	    }
	    else if(a=='I'){
	    	cin>>b>>c;
	        t=n;
	        bool p=true;
	        for(int i=n;i>=0;i--){
	            if(s[i]==b){
					p=false;
					break;
				}
	            t--;
	        }
	        if (t==-1){
				puts("error");
				continue;
			}
	        for(int i=0;i<t;i++) putchar(s[i]);
	        putchar(c);
	        for(int i=t;i<=n;i++) putchar(s[i]);
	        putchar('\n');
	    }
	    else if(a=='R'){
	    	cin>>b>>c;
	        for(int i=0;i<=n;i++){
	            if(s[i]==b) s[i]=c;
	            putchar(s[i]);
	        }
			putchar('\n');
	    }
	}
	return 0;
}