C++ :

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
const int N = 10010;
char ch[N];
int main()
{
    string s;
    getline(cin , s);
    int l = s.size();
    //strcmp相等为0，前一个大返回值大于0，里面可以放数组名字(因为是地址)
    if(strcmp(&s[l-3],"ing") == 0) l -= 3;
    else if(strcmp(&s[l-2],"er") == 0 || strcmp(&s[l-2],"ly") == 0) l -= 2;
    for (int i = 0; i < l; ++i) cout << s[i] ;

    return 0;
}