C program to copy last n characters a string to another string

This function copies the last n characters of a string to another string. For example, suppose string1 contains "Computer Science" ,then copying last 5 characters of string1 will make string to contain "ience".

#include<stdio.h>
#include<string.h>
void strncopylast(char *str1,char *str2,int n)
{   int i;
    int l=strlen(str1);
    if(n>l)
    {
        printf("\nCan't extract more characters from a smaller string.\n");
        exit(1);
    }
    for(i=0;i<l-n;i++)
         str1++;
    for(i=l-n;i<l;i++)
    {
        *str2=*str1;
         str1++;
         str2++;
    }
    *str2='\0';
}
int main()
{
    char str1[]="Computer Science & Engineering";
    char str2[50];
    int n;
    printf("\nEnter number of character to be copied?");
    scanf("%d",&n);
    strncopylast(str1,str2,n);
    printf("str2=");
    puts(str2);
    return 0;
}

Output:

Please comment if you find anything incorrect, or you want to improve the topic discussed above.