#include <stdio.h>
#include <string.h>
int main() {
char s1[] = "azbdcdefghi";
char s2[] = "bxfqcmng";
for (int i = 0; i < strlen(s1); i++) {
for (int j = 0; j < strlen(s2); j++) {
if (s1[i] == s2[j]) {
printf("%c ", s1[i]);
break;
}
}
}
}
/*
run:
b c f g
*/