class string1 {
              // Function to check if a string
              // contains only digits
              public static boolean
              onlyDigits(String str, int n)
              {
              // Traverse the string from
              // start to end
              for (int i = 0; i < n; i++) {
              
              // Check if character is
              // not a digit between 0-9
              // then return false
              if (str.charAt(i) < '0'
              || str.charAt(i) > '9') {
              return false;
              }
              }
              // If we reach here, that means
              // all characters were digits.
              return true;
              }
              
              // Driver Code
              public static void main(String args[])
              {
              // Given string str
              String str = "1a234";
              int len = str.length();
              
              // Function Call
              System.out.println(onlyDigits(str, len));
              }
              }