#include #include using namespace std; int N; long A[1000],B[1000]; long f(long x) { long m,M; for(int i=0;it)m=t; if(i==0||M>N; for(int i=0;i>A[i]>>B[i]; long L=1,R=2e9; for(;R-L>2;) { long M1=(L*2+R)/3,M2=(L+R*2)/3; if(f(M1)<=f(M2))R=M2; else L=M1; } long f1=f(L),f2=f(L+1),f3=f(L+2); cout<<(f1<=f2&&f1<=f3?L:f2<=f3?L+1:L+2)<