#include<bits/stdc++.h>
using namespace std;
#define el "\n"
#define ll long long
#define ull unsigned long long
#define se second
#define fi first
#define be begin()
#define en end()
#define Faster cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);

int main()
{
    Faster;
    string s;
    cin >> s;
    for(auto &x : s)
    {
        if(isupper(x)) x = tolower(x);
        else if(islower(x)) x = toupper(x);
        else if(isdigit(x)) x = '_';
        else x = x;
    }
    cout << s;
    return 0;
}