题解 | 简写单词

#include<iostream>
using namespace std;
int main(){
    string s,result;
    while(cin >> s){
        if(s[0]>='A'&&s[0]<='Z')s[0]+=32;
        if(s[0]>='a'&&s[0]<='z')s[0]-=32;
        result.push_back(s[0]);
    }
    cout << result << endl;
    return 0;
}