A-B

#include <stdio.h>
#include <string.h>

int main() {
    char A[10005];
    char B[10005];
    
    int flag[256] = {0};

    gets(A);
    gets(B);

    int lenB = strlen(B);
    for (int i = 0; i < lenB; i++) {
        flag[(unsigned char)B[i]] = 1;
    }

    int lenA = strlen(A);
    for (int i = 0; i < lenA; i++) {
        if (flag[(unsigned char)A[i]] == 0) {
            printf("%c", A[i]);
        }
    }
    
    printf("\n");

    return 0;
}