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

void Left(char* cipher){
  char variable;
  int len = strlen(cipher);
  variable = cipher[0];
  int a = 0;
  for(a=0; a < len; a++){
    cipher[a]=cipher[a+1];
  }
  cipher[len - 1] = variable;
}

void Right(char* cipher){
  char newVariable;
  int len = strlen(cipher);
  newVariable = cipher[len - 1];
  int a = 0;
  for(a=len-1; a > 0; a--){
    cipher[a]=cipher[a-1];
  }
  cipher[0] = newVariable;
}

void Increment(char* cipher){
  int len = strlen(cipher);
    char hold;
    int i = 0;
    while(i < len){
    hold = cipher[i];
    if (hold >= 'a' && hold < 'z'){
      hold = hold + 1;
    }
    else if (hold >= 'A' && hold < 'Z'){
      hold = hold + 1;
    }
    else if (hold == 'z'){
      hold = 'a';
    }
    else if (hold == 'Z'){
      hold = 'A';
    }
    else if (hold >= '0' && hold < '9'){
      hold++;
    }
    else if (hold == '9'){
      hold = '0';
    }
    i++;
    cipher[i] = hold;
}
}

void Decrement(char* cipher){
  int len = strlen(cipher);
  char hold;
  int i = 0;
  while(i<len){
  hold = cipher[i];
  if (hold > 'a' && hold <= 'z'){
    hold = hold - 1;
  }
  else if (hold > 'A' && hold <= 'Z'){
    hold = hold - 1;
  }
  else if (hold == 'a'){
    hold = 'z';
  }
  else if (hold == 'A'){
    hold = 'Z';
  }
  else if (hold > '0' && hold <= '9'){
    hold--;
  }
  else if (hold == '0'){
    hold = '9';
  }
  i++;
  cipher[i] = hold;
}
}


int main(int argc, char** argv){
  FILE* f1 = NULL;
  char commands[100] = " ";
  int i = 0;
  int a = 0;

f1 = fopen(argv[1], "r");
fscanf(f1, "%s", commands);

if (f1 == NULL){
  printf("No File Found");
}
while(!feof(f1)){
for (a=2; a < argc; a++){
 for (i=0; i < strlen(argv[a]); i++){
   if (argv[a][i] == 'L'){
     Left(commands);
   }
   else if (argv[a][i] == 'R'){
     Right(commands);
   }
   else if (argv[a][i] == 'I'){
     Increment(commands);
   }
   else if (argv[a][i] == 'D'){
     Decrement(commands);
   }
   else {
     printf("No valid cipher command");
   }
  }
 }
 printf("%s\n", commands);
 fscanf(f1, "%s", commands);
 }
fclose(f1);
return 0;
}