Not able to understand why my code is not able to clear any of the test cases

I am getting this error during compiling —
unguard: warning: timelimit exceeded (wall time): aborting command
runguard: warning: command terminated with signal 15

This is my code :
#include
using namespace std;
int main(){
char ch;
long long int ans = 0;
cin>>ch;
long long int n1;
long long int n2;
unsigned short int b=0;

do{
	switch(ch){
		case '+' :
			cin>>n1;
			cin>>n2;
			ans=n1+n2;
			cout<<ans<<endl;
			break;
		case '-' :
			cin>>n1;
			cin>>n2;
			ans = n1-n2;
			cout<<ans<<endl;
			break;
		
		case '*' :
			cin>>n1;
			cin>>n2;
			ans = n1*n2;
			cout<<ans<<endl;
			break;
		case '/' :
			cin>>n1>>n2;
			ans = n1/n2;
			cout<<ans<<endl;
			break;
		case '%' :
			cin>>n1>>n2;
			ans = n1%n2;
			cout<<ans<<endl;
			break;
		case 'x':
		case 'X' :
			b = b+1;
			break;
		default :
			cout<<"'Invalid operation. Try again";
			break;
	}

	if(b==1){
		break;
	}
	cin>>ch;
	
}while(true);

return 0;
}

hello @great
please share ur code using cb ide