#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <windows.h>

using namespace std;

int main() {


	FILE* in;
	FILE* out;
	in = fopen("f1.txt", "r");
	out = fopen("f2.txt", "w+");
	char c;
	while (!feof(in)) {
		fread(&c, 1, 1, in);
		if (c >= 48 && c <= 57) {
			fwrite(&c, 1, 1, out);
		}
	}
	fclose(in);
	in = fopen("f1.txt", "r");
	fread(&c, 1, 1, in);
	while (!feof(in)) {
		if ((c >= 65 && c <= 90) || (c >= 97 && c <= 122)) {
			fwrite(&c, 1, 1, out);
		}
		fread(&c, 1, 1, in);
	}
	fclose(in);
	fclose(out);
}