Help me in solving SESO04 problem

help
,
1

My issue

include <stdio.h>

int main() {
// your code goes here
char s1[20];
scanf(“%s”,&s1);
char s;
scanf(“%s”,&s);
for(int i=0;i<=20;i++){
if(s1[i]==s){
printf(“%d”,i);
return 1;
}
}
}

what is the wrong in this code

My code

#include <stdio.h>

int main() {
	// your code goes here
    char s1[20];
    scanf("%s",&s1);
    char s;
    scanf("%s",&s);
    for(int i=0;i<=20;i++){
        if(s1[i]==s){
            printf("%d",i);
            return 1;
        }
    }
}

Learning course: Data structures and Algorithms
Problem Link: https://www.codechef.com/learn/course/pvp-dsa/PVPDAA13/problems/SESO04