C++ :

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

int box[26];
char c;

int main(){
	while((c=getchar())!=EOF){
		box[c-'a']++;
	}
	int index=0,sum=box[0];
	for(int i=1;i<26;i++){
		if(box[i]>sum){
			sum=box[i];
			index=i;
		}
	}
	cout << (char)(index+'a') << " " << sum;
}