NEW DELHI (AFP) - Whether trudging through knee-deep snow in the Himalayas or astride camels in the deserts of Rajasthan, organisers will ensure no one misses out on a chance to vote in India's elections, the biggest in the world.
The marathon begins on Monday in six remote northeastern seats which are more than 2,000 kilometres from New Delhi. It wraps up six weeks later in the most populous state of Uttar Pradesh, home to the Taj Mahal and the holy city of Varanasi on the banks of the Ganges.
Some 814 million people are eligible to vote, 100 million more than last time round in 2009. That compares with an electorate of some 219 million in the United States, the world's second biggest democracy.
By the time nominations close, there are expected to be around 15,000 candidates from 500 parties vying for 543 seats in the Lok Sabha, or lower house of parliament.
"The statistics are mind-boggling," said Chief Election Commissioner V. S. Sampath as he announced the dates of India's 16th general election last month.
"There are regional, religious, ethnic complexities as well as cultural and linguistic diversities, plus the geographic spread of the country." There will be regional adaptations of the electronic ballot papers to incorporate each of India's 22 official languages.
While tens of thousands of people are expected to file through polling booths in mega cities such as Delhi and Mumbai, it's a different story altogether in other parts of the country.
S. Y. Quraishi, chief commissioner in 2009, recalled how officials walked for four days to deliver voting material to a part of Kashmir's Ladakh region which was home to 37 voters. They rang in results by satellite phone instead of hauling the ballots back to base for counting.
"There were two polling booths at a height of some 16,000 feet. Our air force helicopters made four attempts to land, but in vain, so we had to dispatch two parties by foot in knee-deep snow," Mr Quraishi told AFP.
"It would have been an insult to our voters if we had failed to reach them."
Mr Quraishi, who has written a book of anecdotes over the organisational headaches, recalled how one booth was set up deep in a forest in western Gujarat state where just a single vote was cast.
This year's election will be entirely electronic, but the transport used to deliver the voting machines to some areas remains unchanged since the first one in 1951.
Commission officials will again saddle up camels in the largely desert state of Rajasthan, mules and yaks in mountainous parts of the north, or clamber onto elephants in jungle regions.
Helicopters and speed boats will meanwhile buzz across the Andaman and Nicobar Islands, delivering material to voters on an archipelago made up of 572 islands, 36 of which are inhabited.
Election rules stipulate that no voter should have to travel more than two kilometres to cast their ballot.
"Getting every eligible voter in every corner of the country to vote peacefully is the biggest challenge," said Trilochan Sastry, a founder of the Delhi-based Association for Democratic Reforms pressure group.
Hundreds of thousands of police and army personnel will be deployed to ensure the election passes off smoothly.
A number of militant groups have pledged to disrupt the elections, including in the disputed Kashmir region.
Maoists, who have been waging a decades-long insurgency in central India, killed 16 people last month when they ambushed an army convoy.
As well as guarding the booths, security forces will have to ensure none of the 1.7 million voting machines are tampered with before counting on May 16.
For all the challenges awaiting organisers when the first of nine voting days begins in the states of Assam and Tripura, they know it is a chance to contrast India's democratic credentials with its great rival, Communist-controlled China.
"We have to make sure India puts forward its best foot," H. S. Brahma, another of the five commissioners, told business leaders last month.
"This entire operation does not allow for even a single mistake."