#include<cstdio>int main(){
//1.读入a,Da,b,Dblong long a,b,Pa=0,Pb=0;int Da,Db;scanf("%lld%d%lld%d",&a,&Da,&b,&Db);
//2.对于a,遍历每一位，加在Pa上
//2.1取余的方式遍历while(a>0){if(a%10==Da){Pa = Pa*10 + Da;}a = a/10;}
//	printf("%lld",Pa);
//2.2对b也是如此 while(b>0){if(b%10==Db){Pb = Pb*10 + Db;}b = b/10;}
//3.计算Pa+Pb,输出printf("%lld",Pa+Pb);return 0;
}