```cpp
#include <bits/stdc++.h>
using namespace std;
string s;
int l;
void kongge(){
int l=0;
while(s[l] == ' ') {s.erase(l,1);l++;}
int r=s.length();
for(int i=0;i<r;i++){
if(s[i] == ' '){
i++;
while(s[i] == ' ' && i < r) {s.erase(i,1);i++;}
}
else if(s[i] != ' '){
while(s[i] != ' '&&i<r) i++;
i--;
}
}
return ;
}
bool check1(int i){
/*kongge();
int t=i;
char c[10]="";
int cnt=0;
i-=2;
while(s[i] != ' '){c[cnt++]=s[i]; i--;}
if(c == "or" || c == "and" || c == "not") return 0;
char c1[10]="";
while(s[--t] == ' ');
cnt=0;
i=t;
while(s[++i] != ' ')c1[++cnt]=s[i];
if(c1 == "or" || c1 == "and" || c1 == "not") return 0;*/
return 1;
}
bool check(int i){
kongge();
if(s[i+4]=='f'&&s[i+5]=='a'&&s[i-5]=='t'&&s[i-4]=='r') return 1;
if(s[i+4]=='t'&&s[i+5]=='r'&&s[i-6]=='f'&&s[i-5]=='a') return 1;
return 0;
}
bool check2(int i){
kongge();
if(s[i+3]=='f'&&s[i+4]=='a'&&s[i-5]=='t'&&s[i-4]=='r') return 1;
if(s[i+3]=='t'&&s[i+4]=='r'&&s[i-6]=='f'&&s[i-5]=='a') return 1;
return 0;
}
void solve(){
l=s.length();
kongge();
if(l <= 5){
kongge();
cout << s;
exit(0);
}
if(s[0]=='a' || s[0]=='o' || s[l-1]=='d' || s[l-1]=='r' || s[l-1]=='t'){
cout << "error";exit(0);
}
for(int i=0;i<l;i++){
if((s[i]=='t'&&s[i+1]=='r')||(s[i]=='f'&&s[i+1]=='a')||(s[i]=='o'&&s[i+1]=='r')){
if(!check1(i)){
cout << "error";
exit(0);
}
}
}
return ;
}
int main(){
getline(cin,s);
solve();
for(int i=0;i<l;i++){
if(s[i] == 'n' && s[i+1] == 'o'){
if(!check1(i)){
cout << "error";
return 0;
}
s.erase(i,3);
i++;
int t=1;
while(s[i] == ' ') i++;
while(s[i] == 'n' && s[i+1] == 'o'){
s.erase(i,3);t++;
while(s[i] == ' ') i++;
}
if(t%2){
if(s[i] == 't' && s[i+1] == 'r'){
s.erase(i,4);
string tmp=" false ";
s.insert(i,tmp);
}
else{
s.erase(i,5);
string tmp=" true ";
s.insert(i,tmp);
}
}
}
}
solve();
for(int i=0;i<l;i++){
kongge();
if(s[i] == 'a' && s[i+1] == 'n'){
if(!check1(i)){ //and两边出现not或or
cout << "error";
return 0;
}
if(s[i+4]=='f'&&s[i+5]=='a'&&s[i-6]=='f'&&s[i-5]=='a'){ //双false
s.erase(i,9);
}
else if(s[i+4]=='t'&&s[i+5]=='r'&&s[i-5]=='t'&&s[i-4]=='r'){ //双true
s.erase(i,8);
}
else if(check(i)){ //一true一false
if(s[i+4]=='f') s.erase(i-5,8);
else s.erase(i,8);
}
}
}
solve();
for(int i=0;i<l;i++){
kongge();
if(s[i] == 'o' && s[i+1] == 'r'){
if(!check1(i)){
cout << "error";
return 0;
}
if(s[i+3]=='f'&&s[i+4]=='a'&&s[i-6]=='f'&&s[i-5]=='a'){ //双false
s.erase(i,8);
}
else if(s[i+3]=='t'&&s[i+4]=='r'&&s[i-5]=='t'&&s[i-4]=='r'){ //双true
s.erase(i,7);
}
else if(check2(i)){ //一true一false
if(s[i+3]=='f') s.erase(i,8);
else s.erase(i-6,9);
}
}
}
solve();
cout << s;
return 0;
}
by Cstdio_Rabbit @ 2022-08-16 14:21:06
@[Queue_Hao](/user/486799) 你能解释一下check1吗（已解决RE，但会WA）
by Cstdio_Rabbit @ 2022-08-16 14:21:43
@[Queue_Hao](/user/486799) 实在太长了（
by Cstdio_Rabbit @ 2022-08-16 14:22:16
@[zswmb](/user/235901) 您能先说一下怎样解决RE吗？
是把check1函数注释掉就可以了吗？
by BlackPanda @ 2022-08-16 14:38:04
@[Queue_Hao](/user/486799) emmm我看看（改了一堆，你可以看我提交记录。）
by Cstdio_Rabbit @ 2022-08-16 14:38:55
```cpp
void kongge(){
int l=0;
while(s[l] == ' ') {s.erase(l,1);l++;}
int r=s.length();
for(int i=0;i<r;i++){
if(s[i] == ' '){
i++;
while(s[i] == ' ' && i < r) {s.erase(i,1);i++;}
}
else if(s[i] != ' '){
while(s[i] != ' '&&i<r) i++;
i--;
}
}
return ;
}
by Cstdio_Rabbit @ 2022-08-16 14:39:17
```cpp
void kongge(){
int l=0;
while(s[l] == ' ') {s.erase(l,1);l++;}//l++
int r=s.length();
for(int i=0;i<r;i++){
if(s[i] == ' '){
i++;
while(s[i] == ' ' && i < r) {s.erase(i,1);i++;}//i++
}
else if(s[i] != ' '){
while(s[i] != ' '&&i<r) i++;//&&i<r
i--;
}
}
return ;
}
by Cstdio_Rabbit @ 2022-08-16 14:40:05
@[zswmb](/user/235901) 这样改了就去不掉多余空格了，删除字符之后下标不需要+1吧
by BlackPanda @ 2022-08-16 14:44:56
删除之后，字符串后半段会自动前移吧
by BlackPanda @ 2022-08-16 14:45:37
@[Queue_Hao](/user/486799) 那就会陷入死循环吧
by Cstdio_Rabbit @ 2022-08-16 14:45:53