#include <bits/stdc++.h>
//#define int long long
using namespace std;
signed main()
{
ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
char a;
cin >> a;
if (int(a) = 122)
{
cout << char(97) <<endl;
}
else if(int(a) >= 97 && int(a) < 122)
{
cout << char(int(int(a) + 1)) <<endl;
}
}
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