Can someone help me fix this code

558fe5180e0e8fc922d31c23ef84d240
#include<iostream>
using namespace std;
int main()
{
char LtrGrade;
cout <<"Enter a letter grade: ";
cin>> LtrGrade;
switch (LtrGrade)
{
case "a":
case "A":
cout<<"\nExcellent";
break;
case "b":
case "B":
cout<<"\nSuperior";
break;
case "c":
case "C":
cout<<"\nAverage";
break;
case "d":
case "D":
cout<<"\nPoor";
break;
case "e":
case "E":
cout<<"\nTry Again";
break;
default:
 cout<<"\nNo match was found for the ENTRY"
 <<LtrGrade<<endl;
}
return 0;
}