#include <iostream>
using namespace std;
#include <cstdio>
#include <vector>
#include <cmath>
unsigned i,n,Q,j,L;long long u[66],A;int main(){for(;i<448;i++)u[i/7+2]=u[i/7+2]*96+"+.Uy[e^4MAqc>,3Vq8a}n3-teC`p2r/)Fl[2Z)|>Ke2O~7<Co2:Q]dpI23fM5~22\'X S\'}2\"z;})81lu^+vx1s sc[U1g%Wzq+1s3 ?1[1HQoI$^1TH2EaX1cEzV,Z1CHMY7o1DHmqPA1D#4oe]1F&|\'F^1R`5\'k)0{z2\\Oc1<T/G)x10BVH)~1B,ZzW:1)>FZ%$1+[%c\"<0dAd/tP1->\"0M!1;JwZ6!1*%j_y00V6$w!u10I dHR1PXF]r20!?Xhxw1?nbdEr0e-/ZE_0s:6:z.0[}+qG51<y9WfF0.^#nCQ0s)I(d/0XfrAQB10^,7e?0^X\'W4 13M.MfL0"
"5Q2Oz50fxnC)E0V@NGo+0=Z?sS/0I_*[l0\\W)O u1pw[AYJ/A?Xk;g0rbiYbu1*{Pj>f0\'\"aEs60OP;ZHs0zsjvXg0:~BPSu/aWY+&F1_aM,<q"[i]-32;for(i=0;i<64;i++)u[i+2]+=2*u[i+1]-u[i];scanf("%u",&n);Q=sqrt(n)+1e-7,L=n>>24<<24;A=u[(n>>24)+1]+2*!L*!!~-n;std::vector<bool>S(Q/2+1),B(n-L+2);B[1]=!L;for(i=3;i<=Q;i+=2)if(!S[i/2]){for(j=3*i;j<=Q;j+=2*i)S[j/2]=1;for(j=L?(L+i-1)/i*i:2*i;j<=n;j+=i)B[j-L]=1;}for(i=1;i+L<=n;i+=2)B[i]?0:A+=i+L;printf("%llu\n",A);}
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