process.stdin.resume();
process.stdin.setEncoding('utf8');
 
// your code goes here
 
var pi = 0.0;
var denom = 1;
var sign = 1;
var i = 1;
var prev = 0;
while (true) {
    prev = pi;
    pi += sign * 4.0 / denom;
    if ((Math.abs(prev - 3.1415926) < 1e-7) && (Math.abs(pi - 3.1415926) < 1e-7)) {
        break;
    }
 
    sign *= -1;
    denom += 2;
    i++;
}
console.log('prev=', prev)
console.log('  pi=', pi, 'i=', Number(i).toLocaleString(), 'ith term= 1 /', Number(sign * denom).toLocaleString());

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