// Ces programmes sont sous licence CeCILL-B V1.
void main() {
double a, b, m, e;
e = 1E-5;
a = 2.0;
b = 4.0;
m = (a + b) / 2;
while(b - a > e & Math.abs(Math.sin(m)) > e) {
if(Math.sin(a) * Math.sin(m) <= 0) {
b = m;
} else {
a = m;
}
m = (a + b) / 2;
}
println(m);
}