afin

#include <fstream>
using namespace std;

int main()
{
	int a,b;
	ifstream f("afin.in");
	f>>a>>b;
	char s[10001];
	f>>s;
	int n=0;
	while(s[n]!='\0')
        s[n]=(char)('a'+(a*(s[n]-'a')+b)%26),++n;    ////(a*x+b)mod. 26
	ofstream g("afin.out");
    g<<s;
	return 0;
}