terminate called after throwing an instance of std::out_of_range

[One Pea]

#include <iostream>
#include <string>

using namespace std;

int main()
{
string input;

cout << "Enter a word: ";
getline(cin, input);

for (int j=input.length(); j>=0; j--)
{
cout << input.at(j);

}

cout << endl;

return 0;
}

When I run this program it says "terminate called after throwing an instance of std::out_of_range". Thank you in advance.

[E0p9LyTq]

You are going out of bounds, your starting condition should be input.length() - 1.