1016 部分A+B

#include 
int f(int N, int n);
int main(void) {
	int A, a, B, b;
	scanf("%d%d%d%d", &A, &a, &B, &b);
	printf("%d", f(A, a) + f(B, b));
	return 0;
}
int f(int N, int n) {
	int sum = 0;
	while (N) {
		if (N % 10 == n)
			sum=sum*10+n;
		N /= 10;
	}
	return sum;
}