OJ Board

The following is my code.

In Online Judge, it must run 3's.But limit of the time is 1's, please help me what should I improve my code. Thanks!!

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

int main() {
int count = 1;
string S;
cin >> S;
while ( S != "EOF" ) {
char Letter[26 ...