C++ :

#include <bits/stdc++.h>
using namespace std;

const int N = 209;
string s[N];

void solved() {
	int n = 1;
	
	while(cin >> s[n]) n ++;
	n --;
	
	for(int i = 1; i <= n - 2; i ++) {
		if(s[i] == s[n - 1]) s[i] = s[n];
	}
	
	for(int i = 1; i <= n - 2; i ++) {
		if(i > 1) cout << ' ';
		cout << s[i];
	}
	
	return ;
}
int main() {
	cout << fixed << setprecision(5);
	int t = 1;
	// cin >> t;
	
	while(t --) solved();
	
	return 0;
}

Python :

# coding=utf-8
# 输入字符串 s
s = input()

# 输入待替换的单词 a
a = input()

# 输入将替换成的单词 b
b = input()

# 使用字符串的 replace 方法进行替换
result = s.replace(a, b)

# 输出替换后的字符串
print(result)