#include<stdio.h>

int main()
{
	char s[18]={'\0'};
	char t[]={'1','0','X','9','8','7','6','5','4','3','2'};
	int j;
	scanf("%s",s);
	j=(( s[0]-'0')*7+   (s[1]-'0')*9+ (s[2]-'0')*10+(s[3]-'0')*5+ (s[4]-'0')*8+ (s[5]-'0')*4+  \
	   ( s[6]-'0')*2+   (s[7]-'0')*1+ (s[8]-'0')*6+ (s[9]-'0')*3+(s[10]-'0')*7+(s[11]-'0')*9+  \
	   (s[12]-'0')*10+ (s[13]-'0')*5+(s[14]-'0')*8+(s[15]-'0')*4+(s[16]-'0')*2)%11;
	printf("%s的校验码是%c\n",s,t[j]);
	return 0;
}