一直卡在66分上不去，这TMD咋搞？？?

#include<bits/stdc++.h>
using namespace std;
bool sushu(int n){
	for(int i=2;i*i<=n;i++)
		if(n%i==0) return false;
	return true;
}
bool huiwen(int n){
	if(sushu(n)==false) return false; 
	int t=0,m=n;
	while(m){
		t=t*10+m%10;
		m/=10;
	}
	return t==n;
}
int changdu(int n){
	int ans=0;
	while(n>9){
		n/=10;
		ans++;
	}
	return ans;
}
int main(){
	int n,m;
	cin>>n>>m;
	if(n%2==0) n++;
	for(int i=n;i<=m;i+=2){
		if(changdu(i)%2==0&&changdu(i)!=2) continue;
		if(huiwen(i)) cout<<i<<endl;
	}
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
bool sushu(int n){
	for(int i=2;i*i<=n;i++)
		if(n%i==0) return false;
	return true;
}
bool huiwen(int n){
	if(sushu(n)==false) return false; 
	int t=0,m=n;
	while(m){
		t=t*10+m%10;
		m/=10;
	}
	return t==n;
}
int changdu(int n){
	int ans=0;
	while(n>9){
		n/=10;
		ans++;
	}
	return ans;
}
int main(){
	int n,m;
	cin>>n>>m;
	if(n%2==0) n++;
	for(int i=n;i<=m;i+=2){
		if(changdu(i)%2==0&&changdu(i)!=2) continue;
		if(huiwen(i)) cout<<i<<endl;
	}
	return 0;
}