# Auto-generated code below aims at helping you parse
# the standard input according to the problem statement.

read N
for (( i=0; i<N; i++ )); do
    read P[$i]
done
readarray -t sorted < <(for a in "${P[@]}"; do echo "$a"; done | sort)
lowest=$((P[0]-P[1]))
lowest=$((lowest**2))
lowest='echo "sqrt($lowest)" | bc -l'

for(( i=0; i<N; i++ )); do
    y=$((P[i]-P[i+1]))
    y=$((y**2))
    y='echo "sqrt($y)" | bc -l'
    if [ $lowest -gt $y ] ; then
        lowest=$((P[i]))
    fi
done
echo $((lowest))
# Write an action using echo
# To debug: echo "Debug messages..." >&2