cOutput language typed strings to a text file

#include <stdio.h>

int main(void)
{
    char sts[50];
    int cnt;
    FILE* foc = NULL;
    errno_t err;

    err = fopen_s(&foc, "save.txt", "wt");

    if (err == 0)
    {
        printf("save.txt file created\n");
        printf("1. Enter string : ");
        gets_s(sts, sizeof(sts));

        printf("2. What I wrote in the file: %s\n", sts);

        for (cnt = 0; sts[cnt] != NULL; cnt++);
        fputc(sts[cnt], foc);

        fclose(foc);
        printf("save.txt file close successfully\n");

    }
    else
        printf("Save.txt file creation failed\n";

    return 0;
}