Caesar Cipher

#include <stdio.h>
int main() {
    printf("What operation do you want to execute?\n");
    printf("Press 1 for Encryption.\n");
    printf("Press 2 for Decryption.\n");
    int i;
    scanf("%d", &i);
    if (i==1) {
        int daanebaame, kotoghor;
        printf("Forward or backward?\n");
        printf("Press 1 for Forward.\n");
        printf("Press 2 for Backward.\n");
        scanf("%d", &daanebaame);
        printf("How many positions to move?\n");
        scanf("%d", &kotoghor);
        // nicher kaj ta keno korchi bolo to?
        if (daanebaame == 2) {
            kotoghor = 26-kotoghor;
        }
        char plaintext[100];
        char cyphertext[100];
        getchar(); // eta dite hoyeche ekishathe gets ar scanf use korar karone. google korle aro jante parbe!
        gets(plaintext);
        int a,len = strlen(plaintext);
        for (a=0; a<len;a++) {
            if (plaintext[a] + kotoghor<='Z') cyphertext[a] = plaintext[a] + kotoghor;
            else cyphertext[a] = 'A' + kotoghor - ('Z'-plaintext[a]);
        }
        cyphertext[len] = '\0';
        printf("Your desired Encrypted text is:\n%s\n", cyphertext);
    }
    else if (i==2) {
        char cypher[100], plain[100];
        getchar();
        printf("Cypher text please?\n");
        gets(cypher);
        int ghor,a,len = strlen(cypher);
        for (ghor=1; ghor<=25;ghor++) {
            printf("Forwarding %d position: ", ghor);
            for (a=0; a<len; a++) {
                if (cypher[a] + ghor<='Z') plain[a] = cypher[a] + ghor;
                else plain[a] = 'A' + ghor - ('Z'- cypher[a]);
            }
            plain[len] = '\0';
            printf("%s\n", plain);
        }
    }
    else {
        printf("Vai thik moto input den na ken? :'(\n");
        printf("Abar notun kore shuru koren!\n\n");
        // nicher kaj ta interesting na? Ki hobe bolo to? :p
        main();
    }
    return 0;
}