题解

#include <iostream>
#include <string>
using namespace std;

int main() {
string s;
cin >> s;
int b[26] = {0};
for(char c : s) {
b[c - 'a']++;
}

int c = 0;
char result = 'a';
for(int i = 0; i < 26; i++) {
    if(b[i] > c) {
        c = b[i];
        result = 'a' + i;
    }
}

cout << result << endl;
return 0;

}