#include <iostream>
using namespace std;
int main() {
char text;
int countLetter = 0, flag = 1;
while (flag == 0) {
cin >> text;
if ((text >= 'a' && text <= 'z') || (text >= 'A' && text <= 'Z')) {
++countLetter;
} else {
flag = 0;
}
if (flag == 0) {
break;
}
}
cout << countLetter;
return 0;
}
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