Exercise 7-10 finding specified characters (15 points)

#include <stdio.h>
int main () {
    
    int i=0,ret;
    char ch;
    int flag=0;
    char a[81];
    scanf ("%c\n",&ch);
    gets (a);
    for (i=0;a[i]!='\0';i++) {
    
        if (a[i]==ch) {
    
            ret=i;
            flag=1;
        }
    }
    if (flag==1) {
    
        printf ("index = %d",ret);
    } else {
    
        printf ("Not Found");
    }
    return 0;
}