import std.functional,
       std.algorithm,
       std.bigint,
       std.string,
       std.traits,
       std.array,
       std.range,
       std.stdio,
       std.conv;

void main() {
  int[] XYZ = readln.chomp.split.to!(int[]);
  int X = XYZ[0],
      Y = XYZ[1],
      Z = XYZ[2];
  int n = X - Z;


  writeln(n / (Y + Z));
}