ex_str

#include <stdio.h>
#include <stdlib.h>

int main () {
    int n = 15, m = 10;
    char *s1 = malloc(n*sizeof(char));
    char *s2 = malloc(m*sizeof(char));
    char c1;
    char c2;
    int i = 0;
    int k = 0;
    while (c1 != '\n') {
        scanf("%c", &c1);
        s1[i] = c1;
        ++i;
    }
    while (c2 != '\n') {
        scanf("%c", &c2);
        s2[k] = c2;
        ++k;
    }
    for(int j=0; s1[j]!='\n'; j++) {
        printf("%c", s1[j]);
    }
    for(int j=0; s2[j]!='\n'; j++) {
        printf("%c", s2[j]);
    }
    int index = -1;
    for(int i1=0; s1[i1]!='\n'; i1++) {
        for (int j1 = i1, k1=0; s2[k1]!='\n' && s1[j1]==s2[k1]; j1++, k1++) {
            if(k1>0 && s2[k1]=='\n')
            {
               index = i1;
               break;
            }
        }
    }
    printf("%d", index);
}